This EVGA GTX 670 FTW will beat even a reference GTX 680 out the box while costing $100 cheaper. It's a bit pointless to buy a reference GTX 680 when this card beats it in most games.http://www.newegg.com/Product/Product.aspx?Item=N82E16814130787http://hexus.net/tech/reviews/graphics/40613-evga-geforce-gtx-670-ftw/?page=5
Also, if you game at 1920x1080 resolution, you will only need the 2GB version. You would need 4GB if you are running surround view (3 monitor setup)
You can max out BF3 with just 1 EVGA GTX 670 FTW above 60+ FPS.
This card in SLI would be only $800 and would stomp even a reference GTX 680 SLI setup for $200 cheaper.