I came from Google Photos. Loving iCloud Photos. I've got 136 GB, over 70,000 videos and photos. The ability to take a photo, have it instantly available on my Mac, iPad, and iPhone is amazing.
My experience was quite different. I'm also a long time user of Google Photos. I decided to try iCloud Photos. I have about 45,000 photos on my iMac organized into a semi-complex
folder structure:
The import into iCloud Photos took over a week and constantly crashed. (I supposed this is because I told it to preserve the directory heirarchy. But, why would Photos balk at folders nested two or three deep?)
But, what really bothered me was that all the photos on my iPhone and iPad were "optimized"; even though both devices had about 32GB available storage when I turned iCloud Photos
on. This meant that every photo I took was immediately stored in iCloud and my phone and pad had only icons and/or low resolution versions.
So, I'm on an airplane coming home from a dive trip. I'd like to kill the flying time by editing a few photos. Sorry. Can't do it. All the photos are "optimized" and you have no Internet, so no way to edit.
Another annoying scenario: I'm in line at a coffee shop. I snap a pic for later upload to Instagram. I place my order and sit down. Let's edit that photo. Sorry, it's already been optimized so you have to wait until it downloads to edit. Edit the photo and go pick up my coffee. Ready to upload to Instagram. Sorry, you have wait again until the photo downloads from iCloud so you can upload it to Instagram.
To me, this seemed like horrible cloud storage management. Why not leave full resolution versions on the phone for a while. Let the user choose. Leave the most recent 1000? Leave the photos I've taken in the last two weeks? Leave all until they've consumed 10 GB of space? Anything but optimize them all.
So, I turned iCloud Photos
off. And, yeah, all the photos were gone. Fine. Instead I was left with hundreds and hundreds of empty folders in the Photos app all of which have to be deleted individually.
So, I use My Photo Stream instead. It does what I want which is keep full resolution versions of recent photos on both my iPhone and iPad. I use DropBox Camera Uploads to automatically save full resolution versions to my iMac. I use Google Photos as sort of a last-resort backup and in case I want to look at an old photo when I'm out and about.
Of course, YMMV.