So, I upgraded the day before yesterday and all in all I am quite pleased with it. Here are some of my pros and cons so far.
*new dock. I just thought the GB one was such an eyesore! This one is largely transparant and brings out the shape of the screen a lot better. The entire UI overhaul is an improvement imo.
*new gallery. Looks better, more functional and works a lot faster
*the ability to switch of apps! Halleluja, praise the Allmighty! The peformance manager was a dissappointment but if you root through your app settings, it turns out you can switch off a bunch of apps! Switching it off also hides it from the app tray. I used it to kill a load of useless bloatware and my RAM use is looking quite acceptable.
*scrolling in a browser is a lot slower and laggy. I switched to boat browser mini, which does it a lot better though.
*A too high resolution wallpaper makes swiping your homescreen lag.
*apps that are removed or switched off have the nasty tendency to not go away. It's bad enough that I cannot get rid of "Fun and Downloads" and that it is always running, but when I tell it to quietly sit in it's corner I do not want to see it in my cache eating up my precious RAM.
Also, I uninstalled UEFA.com 4 times.
*screenshots are gone!
That made me sad because I actually used it (Edit: found it! It is power+ volume down now)
For more I shall keep playing