I think you are right to an extent, but my experience is not quite the same as you describe.
With my old setup of non-Apple routers/access points, the Apple devices and other devices would hang onto the last access point to which it connected, until the signal was so bad it was undetectable, and then it would switch. ie. I'd be roaming around the house and it'd drop to say 3 Mbps and then eventually disconnect, and then would switch over to a closer access point. Obviously this is not ideal.
However, that has not been my experience with my AirPort Extreme network. It wouldn't always stick with the fastest access point, but it doesn't hang on forever to the last one it connected to either. It's somewhere in between. So what I'd get is an Apple device getting say 500 Mbps right next to the access point, and as I roam it would hang onto it to a certain extent. For example if I went downstairs and toward another room, it might give me 90 Mbps, but if I hung around there for a while it might eventually switch to the closer access point at 225 Mbps. During this period I would not notice any disconnection. The switch would be invisible to me.
So, that's not quite the same as truly actively managed mesh system, but it's good enough for my usage since my target end point is to have speeds that don't affect video streaming even at 4K everywhere in my house. With this many units in the house, I have achieved this, for a reasonable cost. (The last AirPort Extreme 6th gen I bought was ~US$30, and the last AirPort Extreme 5th gen was ~US$15.)
This was an issue in our yard too. I recently installed two (!) AirPort Extremes in the backyard, so now I get 30+ Mbps everywhere there... and sometimes 500 Mbps.
I have a 6th gen in a shed, and and a 5th gen in my gazebo. This is the custom mount I hacked together for the 5th gen:
Out in my backyard I have a gazebo with an electrical plug, and several years ago I ran outdoor Ethernet cable to it for internet access. However, I've been using el cheapo third party access points out there, cuz it's outside and it's infrequently used. In my house, it's an all Apple AirPort...
forums.macrumors.com
The AirPort Extremes outside so far don't seem to mind our Canadian winter at all. We'll see how they handle the heat in the summer, but I suspect they'll be fine since the el cheapo non-Apple unit I had in the gazebo before worked fine for many years until I finally disconnected it this weekend.
I was curious what the max speed I could get out of this AirPort Extreme 6th gen would be. To my surprise, using a 2017 iMac Core i5 I can get over 850 Mbps on WiFi. Here is the Speedtest result with Ethernet disconnected. (Wired is well over 900 Mbps.)
View attachment 1727303
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Note that the iMac is the only device in this house capable of this, as it has 1300 Mbps WiFi link with the AirPort Extreme. It's also sitting close to the AirPort Extreme on the same table. My 2017 MacBook Core m3 is more in the 500-600 Mbps range as you describe.
I'm sorry I wasn't as clear I should have been when I said:
I was often getting about 150-250 mbps on some devices (and 500-600 mbps routinely on the devices right next to the access points). We have Gigabit internet with Comcast that runs 700-940 mbps on most things that are wired, and right now my wired Apple TV in the family room is showing 743 and the iMac is wired and showing 848. But because the Airport Extremes upstairs and on the main floor sit behind a computer monitor and TV, the signal was blocked in some places and ran slower (25-100 mbps). That is fine for streaming, but for doing fast time machine backups or copying many files to the server not so much. Also we got only 2-20 mbps in the yard.
That meant that I would get 500-600 right next to the 6th Gen AirPort Extreme, but as I moved away from the 6th Gen the speeds would drop as low as 25-100 mbps in many cases as I would move around, instead of switching to the 6th Gen AirPort Extreme that was closer.
The signal strength at 25-100 mbps was apparently still good enough to hang onto the previous Airport Extreme (probably better than -70 dbm is my guess) for a while. But it was only in the master bathroom or when outside that it went below 50-75 mbps, going as low as 25 mbps in the bathroom with my iPhone or iPad. I was usually getting above 75-100 everywhere else, and 150-350 mbps in the same room as the 6th Gen when not moving around.
Some more thoughts, and tests...
I had one 6th Gen AirPort Extreme set up as my router in the basement, a second one wired as an access point in the main floor master bedroom, and the third one wired as an access point upstairs in my son's bedroom on the other side of the house (staggered middle of house > south end > north end, from bottom to top) with all connected via ethernet Cat 5e cable pre-wired in the walls. The one in the basement was just below the main floor family room and dining room in the middle of the house, so most of the time we would connect to that one when we were home (front or back door).
The basement 6th Gen was removed when we put the Asus GT-AX11000 router is in its place, and I was just keeping the old network for smart home and cameras through the two 6th Gen access points on the old SSID in the main floor bedroom and upstairs loft. The Asus mesh is on a different SSID (old name + AX at the end) with one on the basement, and an AX92U in the family room behind the 55" TV and another in my son's bedroom on the north side of the house.
Before, if we came into the house through the garage, we'd 1st connect to my son's bedroom Apple access point above the garage, and it would take a while to switch to the router under the family room where we'd hang out, but speeds were still 150+ mbps when connected to the one upstairs in his room, so the signal was not weak. Eventually clients did switch to the one under the family room and speeds would double. But it always took a while, if at all.
But, then if we moved from the family room to the other rooms it would stay connected to the basement, since the signal was still strong enough most of the time, unless we stayed closer to another 6th gen for a long time (like going to sleep in the same room with another access point for example, we'd wake up connected to the one in our room).
Although I'd get 25 mbps in my master bathroom farthest from the access points, like when the iPhone or iPad was hanging onto the basement 6th Gen router, I didn't stay in the master bathroom long enough for devices to automatically switch from the basement to the bedroom. Today on the Asus AiMesh network I walked from the family room to the master bathroom and just got 395 mbps there with my iPad Mini 5. Meanwhile, my 16" MacBook Pro just got 455 mbps in the family room, neither having WiFi 6! This is much faster than we used to get.
Before the AiMesh, taking my MacBook Pro from the family room to the bedroom during a TimeMachine backup would make a 20 minute backup take up over an hour, even though there was another AirPort Extreme in the bedroom, because it was still connected to the one in the basement at 75-100 mbps. During a TimeMachine backup I'd guess that Apple would prevent it from disconnecting from one access point to connect to another if my signal and speeds were good enough. As you stated, even you had to hang around for a while to see it switch from one access point at 90 mbps to another at 225 mbps.
My spot in the family room where I started out was a little diagonally above the 6th Gen in the basement, and I would see 150-250 mbps with the Apple network. Because the signal was still strong enough as I moved away, it wouldn't let go of the basement and connect to the bedroom 6th Gen, where I'd see 75-100 mbps when sitting in my bedroom chair. The bedroom 6th Gen is behind the TV by the wall 10 feet away from my chair but next to the ethernet jack, and I have hard wired my SmartTV, ATV, and Xbox into the 6th gen LAN ports. Waking up in the morning I would find that all my devices had switched to the 6th Gen in the bedroom, but I could not know how long it took to switch as I was asleep when it happened.
With the Asus AiMesh network I usually get over 250-300 mbps just about everywhere, and up to 455 right now on my MacBook Pro 16" when traffic on Xfinity is low, which is about 2-3x faster than my speeds with the Apple network. As I said, right now I'm seeing 455 mbps which is almost 2x faster than the old network was.
See Speedtest results below, with tests done before 2/6/21 being on the Apple network, and the most recent 3 MacBook Pro speed tests being on the Asus AiMesh network. I have done most of my speed testing in the family room spot with my iPhone and iPad, not the MacBook, but you'll see a similar trend with jumps in speed after the upgrade. The iPhone's slowest double digit speeds were done in the bathroom and single digit outside with the Apple Network prior to 2/4/21.
16" Macbook in family room before and after upgrade Feb 4th (6th Gen router in basement with access points in master bedroom on main and son's bedroom upstairs up until Feb 1st):
iPhone 11 Pro Max below, before and after upgrade middle of the night, Feb 4th:
The two slowest single digit speed tests on 2/2/21 were done outside back to back.
The slower double digit speed tests (18-29 mbps) were done in the master bathroom on two different days.
I currently have the Asus network set to let it switch to a stronger node when the signal strength drops weaker than -68 dbm (default was -70 which would have on longer before switching -
www.dongknows.com estimated the -70 is about 2 bars of WiFi strength on the Asus, whatever that means - different brand, different bars).
Lastly, I before I typed this reply I had hooked up the previous 6th Gen router to the kitchen behind the iMac as a 3rd access point (all Apple in bridge mode) using the apple network's SSID. I plugged the iMac into the back of it and left the other two 6th Gens in my master bedroom and the upstairs loft. This gives me three Apple 6th Gen access points again, all wired into the Asus router in the basement, but without an Apple in the basement anymore. I have been sitting right in the middle of the two 6th Gen on the main floor, 15 feet away from the bedroom 6th Gen on the other side of the wall, and 15 feet from the 6th Gen in the kitchen, 35 feet from the one in the upstairs loft at the front of the house.
I had connected my iPhone 11 Pro Max to the old network SSID after that, when I started typing this post, and I just went outside and tested the speed in the back patio. I got 5.94 mbps down and 3.10 mbps up, with it having connected to the bedroom Apple 6th Gen access point automatically.
While on the patio I switched my iPhone to the Asus WiFi network SSID and I got 15.6 mbps down and 6.39 mbps up. So, the Asus is running 3x faster outside for download, and 2x faster with uploads. I didn't have a way to check which node I was connected to, but the most direct line of sight to the back porch was with the GT-AX11000 in the basement.
Apple 6th Gen network outside on back patio:
Asus AiMesh network outside on back patio:
Then, while standing next to the 6th Gen in the kitchen I switched from the AX network back to the Apple network and tested the Apple network speed outside on the patio again. I got 12.7 mbps download and 19.2 mbps upload speed. I confirmed that the iPhone 11 Pro Max was connected to the kitchen 6th Gen AirPort Extreme. Note - the kitchen 6th Gen access point is closer, with 1-3 less walls or floors to penetrate, than the Asus AiMesh router and nodes in my basement, bedroom, or son's bedroom.
After testing the speed outside, I walked back into the family room while still on the Apple network and saw 210 mbps down and 40.9 up, still connected to the 6th Gen access point in the kitchen. A repeat test confirmed a stable 226 down and 41.6 up.
Switching to the AX network while in the family room, without moving the iPhone, gave me 457 mbps down and 41.5 mbps up! Visiting the router webpage says I'm connected to the family room mesh node now:
I walked outside and tested the speed again on the back patio, while still connected to the AX mesh network on the family room node, and got 235 mbps down and 27.8 mbps up!
So I have to assume with my first AiMesh test when I was on the patio and chose the mesh network, that the iPhone connected to the basement AX router but I should have checked before I started.
I had checked to see which 6th Gen I was connecting outside to because it's easy to check with Airport Utility, rather than logging into the router. So, point would go to Apple for ease of use when tied to the Apple ecosystem and having the airport utility on every device. But I just discovered the Asus app and turned on settings to allow me to access the router, and now I can remotely see what is connected to where on the Asus mesh network too.
If I turn WiFi completely off and back on with my iPhone 11 Pro Max on iOS 14.4, even though it was connected to the faster Asus AiMesh AX network before, it comes back up on the old network connected to the 6th Gen Airport Extreme. So, I had to forget the Apple network on my iPhone 11 Pro Max in order to always reconnect on the faster WiFi 6 connection if I have turned off WiFi or disconnected (my iPhone 11 Pro Max is the only mobile device using WiFi 6 currently).