Fedora 22 is out, go get it.
I use KDE so the I'm using the new Plasma UI. Some of my apps are getting confused about the system tray. Haven't dug in to deeply yet.
The worst thing though is the mouse input. I spent a good while troubleshooting my gaming mouse thinking a light drop from earlier in the day had broken it somehow. Small mouse movements were really slow or lost altogether. It's pretty terrible in a game when you're using it for aiming and the mouse doesn't move.
I found the KDE input setting and set acceleration and settings to what I thought should make it better but it was still dropping inputs, particularly when changing direction in small motions.
Turns out Reddit had the answer.
That linked me to:
Basically, uninstall the new input library.
Mouse scroll is pretty terrible with my work mouse barely moving at all for the "Add Activities" window when I was trying to add something to the new KDE desktop. Changing the scroll by 3 lines to 12 lines didn't help at all there. I'm going to remove that package on that computer too.
I should probably contribute a bug report.
Otherwise, Fedora 22 is looking nice so far.
One new systemd feature I'm really appreciating is the new control+alt+delete handling.
I had a graphics driver crash for unrelated reasons which caused something to hang. I mashed control+alt+delete in frustration and was pleasantly surprised when it said "Ctrl-Alt-Del was pressed more than 7 times within 2s, rebooting immediately." when I was expecting to have to hit the power button.