The problem with the official samsung/carrier upgrade is I doubt you’ll notice any difference. Touchwiz is Touchwiz in any version of android.
Have a look here [/url]for a list of roms.
I’m currently using Pure ICS from here
I’m also using the 15 toggle mod from here which allows you to modify the notification bar toggles.
It’s working pretty well the only issue I have is some of the dialogs are black text on a grey background so not that easy to read but they are only in a few places.