If I could easily go back to kit Kat I would.
The pros to lollipop:
The phone is noticeably smoother and there are a few UI features that are nice upgrades. Being able to customize the second favorites Edge is great. The aesthetics to lollipops Material Design look clean. And I'm guessing the SD card thing is great but that doesn't effect me.
The cons:
I did like the camera shutter button on the edge. What they did to the lock screen is horribly inconvenient for controlling music on the fly. When I drive I put my phone in a dash mount and blue tooth my music. By taking away the lock screen widgets and only giving us tiny control buttons it has taken a step backwards for functionality.
I also don't like looking at my lock screen and being forced to see a bunch of white rectangles. For an os that prices itself on customization they took a step back there too.
I guess now I'm hoping the next update fixes some of these issues. Part of me wishes the phone was more popular so it would be worth it for developers to produce more apps that fix some of these problems as well as more Edge apps.