Have been using Silverblue for the past few years as my daily driver. Definitely a game changer, have all of my apps installed in a toolbox or via Flatpak. Can honestly say I have never had a system this stable before.
I started using it a couple of weeks ago and while I love the idea, I still feel there is some unsolved issues. I.e. Powerline does not work that well, accessing serial ports (microcontroller programming) requires a weird hack that is not fully working.
It is definitely usable and even good, but there is edge cases that ere not figured out, I feel. It needs more blog Posts, Docs, Tutorials ...