On my iMac it feels better, although I have to say it's a top-specced machine, but I've heard similar reports from friends with Macs - no Mavericks-like sluggishness and less bugs overall. However, one outstanding bug for me is that the iMac can't sleep without crashing, but with sleep turned off it runs like a champ, no other complaints or issues. Thankfully, my Macbook Pro remain unaffected, a good thing since no sleep would be fatal for a laptop.
All you have to do is click once on the app you want to change back and hit command and i then click on the app icon in the top left corner then hit command and x and it should change back. hope this helps! Have an awesome day!