As of right now my PC looks like this:
E8400, 790i, EVGA GTX 260, 4 gb OCZ 1600 DDR3, velociraptor 300gb + WD500gb drive (storage), powered by corsair tx750w, enclosed by antec 902 case. I have a single monitor (samsung xl2370, running at 1920*1080).
I've never actually owned an AMD/ATI card, primarily due to issues with the drivers... Will this "unlock" void the warranty of the card?
No, that's what I mean by ""legally"" because AMD put it there and you can flash it back if you need to RMA for any reason or sell it. Only the 2GB versions can be unlocked though and as I said, it's $85 cheaper than the cheapest GTX570.
The drivers I've heard are improving and if you don't have CrossFireX then you shouldn't get any significant issues.