In terms of price vs performance. Doing a new build currently under $1200 with HIS 7970 and wondering if it would make that much of a difference going to a 7970 or 670?
HIS 7950 IceQ X² Boost Clock 3GB GDDR5 PCI-E
http://www.newegg.com/Product/Product.aspx?Item=N82E16814161429
GIGABYTE GTX670 Windforce
http://www.newegg.com/Product/Product.aspx?Item=N82E16814125423
SAPPHIRE Radeon HD 7970 3GB
http://www.newegg.com/Product/Product.aspx?Item=N82E16814125423
HIS 7950 IceQ X² Boost Clock 3GB GDDR5 PCI-E
http://www.newegg.com/Product/Product.aspx?Item=N82E16814161429
GIGABYTE GTX670 Windforce
http://www.newegg.com/Product/Product.aspx?Item=N82E16814125423
SAPPHIRE Radeon HD 7970 3GB
http://www.newegg.com/Product/Product.aspx?Item=N82E16814125423