It depends which side you mean. The server works flawlessly for me and the desktop apps for synchronization have been very good.
The Android app is okay. I've been having difficulty lately with getting photos to automatically synchronize with it from my phone. I ended up using a different app (Folder Sync) to do that and it works fine now.
It's a lot better than I remember
Mind you, I'm only trying to make it work for myself, not a whole lab of people
But even still, the RSS reader might be worth it alone haha
Okay never mind
The RSS reader isn't updating
Sorry you had that experience. I've never gotten that on the stable channel. Were you updating from 12 to 13? There's a command you can run to switch of maintenance mode.
Did you set up nextcloud to use a system cronjob? The default Ajax triggered cron doesn't have the ability to update the rss feeds.