For me ICS is an UPdate, it is faster now, because ICS kills apps automatically if there is little ram memory. My quadrant benchmark is really bad but i think it comes because of my launcher
(TSF Shell). I can play games like frontline commando etc. Only MC3 and asphalt you can't play without any lag. I'm very happy with the update.
If i was you i would do an update.
Sorry for my bad english, i'm dutch.