Graphics Card:
Since you mention the GTX670, here's my GTX680:
http://www.newegg.com/Product/Product.aspx?Item=N82E16814121634
Older review:
http://www.hardwarecanucks.com/forum/hardware-canucks-reviews/55064-asus-gtx-680-directcu-ii-top-review-11.html
Benchmarks will have changed for all cards slightly due to drivers. Some games saw up to a 20% improvement with this card versus a stock GTX670.
NOISE:
This is the QUIETEST card under load with this level of performance. A big part of the reason is the massive heat sink (it's a 3-slot card). I didn't need the extra slots and the backplate and three screws mount it in solidly; no worries of bending.
*NOISE is a very, very big deal to many people. Poor graphics card and CPU coolers are the biggest noise makers. Unlike CPU's however, the cooling solution on a graphics card is not easily changed. DO NOT get a reference cooler design.
There are HD7970's now with similar performace (though it's back and forth between games) however raw performance isn't the entire picture. (PHYSX, TXAA, *GPU BOOST, Geforce Experience, Adaptive VSYNC).
What is Adaptive VSYNC?
http://hardocp.com/article/2012/04/16/nvidia_adaptive_vsync_technology_review/
SUMMARY:
- GTX680 DC2T ($520) is the fastest 600 series and back and forth with the FASTEST of the HD7970's
- Make sure to get a good COOLING solution, and look at the Warranty/quality etc.
- Make sure to REDEEM your game coupons ASAP after buying the card.