I have been using it for I think over a year now as my only phone, on a Samsung Galaxy S9+. It's honestly not much different from Android (although a little out of date), and the only real issue I have is that installing software is a little inconvenient. (The built in app store doesn't work reliably.)
Right. It's fine for me since I use free software as much as possible anyway. The only applications I've sideloaded are WeChat, Teams, Discord, Target, Instagram, and WhatsApp, all of which work fine.
Edit: and Google Maps. The built-in mapping software doesn't have good enough traffic estimation.