Upgraded to Kitkat
Just decided finally to take the plunge(India ZL user). Upraded to Kitkat today.
Process was smooth enough. For the time being atleast, I dont see any battery drain from google services. Will post the update afterwards.
In fact battery life seems little better than earlier. But I disable all location services and enable it only when needed. Google now is on, but location based features are disabled. But thats the same I used to have in JB.
Notification bar is jittery, but thats ok. When you pull it down, animation is jerky and not smooth like it was in JB. But I can handle that. No major issue there.
Settings panel is ok as well, I dont see any difference.
As for the changes, its almost similar to JB, minor UI changes here and there. Settings are now more organized.
Only noticeable change is that notification bar is now better(I like this way, actually). When you want to change any setting, go to quick settings, else there is now more room for notifications. And you now get true fullscreen in games, watching videos etc. With swap from the top, you get notification bar and soft keys in full screen, else its not shown.