I use the Sapphire 4870 1GB and I run the game on all settings ultra, 1080p but no AA and I get an avg. of 30 FPS or more. Even in the most intense battles the game runs smooth, so it's a good purchase. However, I would recommend grabbing the Sapphire one over this. Because it's $10 cheaper, better heatsink and adjustable fan speed. here's the link :
http://www.newegg.com/Product/Produc...82E16814102801
Edit
I actually bought the Toxic edition which at the time was the same price. It has better cooling than the regular edition and it's overclocked.
http://www.newegg.com/Product/Produc...82E16814102815
But now it's going for a good $50 more.