My RCS experience actually improved dramatically on the previous DB. It was shaky (inconsistent) at first, as you said, but has only improved each successive beta release.
This is my RCS timeline:
- DB3 (first install of iOS 18 for me) works flawlessly except on wireless CarPlay, where it stops working and takes a while to recover after disconnecting
- DB4 stops working on various wifi networks, introduces the RCS/SMS flicker (e.g. when you‘re on wifi and turn wifi off, it goes to SMS and takes a few seconds to show RCS again), RCS periodically becomes stuck as SMS, even with good cellular connectivity
- DB4.5 only noticeable issue I encountered so far is the RCS/SMS flickering is still present but always goes back to RCS again after a short while. I‘m soon going to drive somewhere, I‘ll verify the wireless CarPlay and cellular issues I had. //
EDIT: it still does not work on wireless CarPlay and it took a long time to reconnect, so long that I have no idea how long it took (I periodically checked a RCS chat while I was grabbing groceries. By the time I got back to the car it had mysteriously reenabled itself, only to go away again when CarPlay connected). Seems like CarPlay poisons RCS for me oh well I don‘t text and drive anyways
I think Apple has designed RCS to be very aggressive about data connections, unlike iMessage. Like when you have 1-2 bars, it simply wont go RCS for me. iMessage meanwhile is a true permanent addition to your contacts presence / chats. It is not as aggressively at purging iMessage state from conversations as RCS (the second you‘re with a crap connection it goes off, even when it could realistically send out RCS texts that maybe take a while to send).
Not to mention the group chat issue that plagues RCS, documented in the other topic "RCS supported carriers" (tldr Apple does a big no-no and lets you send SMS into a RCS group when you are disconnected temporarily from RCS, which permanently bricks the group to SMS on iOS and starts a new SMS group chat for every Google Messages participant, whereas Google does it properly and simply wont let you send a message at all if you can‘t send RCS).