GSM Arena reviewed the sgs2 again this time with ICS upgrade!Read here
The conclusion:If you're asking whether it's worth updating your Samsung Galaxy S II from Android 2.3 Gingerbread to 4.0 Ice Cream Sandwich, the answer is an unequivocal yes. The user experience improves in multiple areas and there's nothing lost after the update.
Ice Cream Sandwich will extend the Galaxy S II's life and it will continue to be a highly popular device. We certainly saw plenty of competitors at the MWC compare their devices to the S II.
Looking further ahead, an upgrade to Android 5.0 Jelly Bean is less certain. We hope the S II will have more luck than the original Galaxy S, which Samsung couldn't update to ICS, but we'll just have to wait and see.
Anyway, the Samsung Galaxy S II is one of the first phones out there with Ice Cream Sandwich and will continue to enjoy near premium status (though not flagship status after the S III finally arrives).