With 10.00 off instantly, and 30 dollar rebate. 75.00- Thats a excellent deal. I get great performance from the xfx 4770. Without voltage adjust I run at 920/1000 VS 750/800 . I've read that Asus supports voltage tweak.
Yeah, the memory on the cards is the same speed so obviously go for the cheaper 1gb card. Another card to consider is the HD4850. It's a bit better and can be had for $95 which is less than the initial cost of the HD4770(no rebate tho.)