Hey Fazz - two things.
1. Could you post the full specifications of your PSU? Amps on 3.3v Amps on 5v etc and maybe a name and serial number if you can find it?
2. One advantage the ATI cards have is direct x 11/10.1. Now direct X 10.1 isn't supported by everyone, but a few companies will support it now and when games are released that are direct x 11 compatible they will also be direct x 10.1 and that gives a very nice boost to ATI cards like in games such ass Assassins creed.
Tease.