Yeah I don't know how much it's improved since earlier builds but things that weren't available were full hardware acceleration, Samsung Dive (which will never work on it so we can forget that anyway) and there were SD card reading issues as well.
If those are fixed then I will give it another shot I guess but the one thing that I do not like is the lack of Contact Group support, All ROMs from Samsung/HTC etc support the ability to manage contact groups on your Google account but AOSP ROMs do not which I think is stupid to the max.
ICS better have the ability else I won't be pleased!