That's a good card, but a GTX 480 OC'ed could easily reach GTX 580 performance. It's a bit warmer and uses a bit more juice over the 7850.
Out the box, the GTX 480 is faster than the HD 7850 and OC'ed surpasses it as well as this card OC's well too like the HD 7850. The 1.5GB VRAM on the GTX 480 will help a lot in Battlefield 3 on Ultra at 1080p. The HD 7850 has 2, but at 1080p, the 1.5gb the GTX 480 has is more than enough.