ICS, my 2c...
Call quality seems the same [good].
Direct dial shortcuts disappear from the desktop repeatedly.
GPS is better, but also much aided by GPS Test Plus.
I don't like the different way of adding stuff to the desktops.
I can't remove the google earch bar from the desktops.
Data usage app [inc data cap] is a great addition especially being able to block background data usage when on mobile networks.
Battery life seems about the same - ie not great
Screen brightness auto setting now seems to work as you'd expect.
Gallery renamed to "social gallery" - what on earth for?
Overall, an improvement, I think.