IMO,your best bet is to remain on GB firmware. unlock and root,and you can run ICS custom roms by flashing a firmware patch. the leak firmware has caused issues for some.
if your game for s-off,do that FIRST,then you can run the leak RUU.
if you dont want to root and unlock,then continue to have patience. the leak ruu runs pretty good,but you will be stuck with it untill newer RUUs come out,with s-on.
last and not least,you will likley not OTA to official ICS from a leak. the updater scripts send to look for official release build numbers,so youll need to be on 2.01.605.11 in order to OTA.