From what I remember of using this phone anything above 2.3.3 or cm7 will be vary laggy and unstable the prevail isnt strong enough to pull ICS or jb cm7 by hoark13 has been the best ROM this phone has seen as well as blooddawns ct mod and other many more unfortunately my prevails (both of them) stopped working one is hard bricked from trying to port twrp and the other was dropped in a cup of soda) : such a sad way for them to go but there in a better place now *sniff sniff* Lol anyway the drivers for the camera has changed from 2.3.5 in the 4.0 updates Google did this.
I haven't used the prevail in so long I think maybe a lot has changed but I wouldn't get your hopes up I'm happy to know people still use the prevail im using its older brother sg2 let me say kicks ass