They are pretty impressive in crossfire, especially in Metro, I thought there was something wrong with the results when I saw they were on par with a 590/6990
If you want a cheap crossfire set up for £202 two of these are worth it, but for a single card, as said in the review the 6850/70 are the better cards to go with.
NZXT Switch 810 - i5 2500K - Gigabyte Z68 UD3H - 8GB 1600mhz Mushkin Blackline - Zotac 970 GE - Crucial MX100 256GB SSD - Samsung F3 1TB HDD - Corsair H100 - Corsair HX850 - Asus VE247H
PC Audio: Asus Xonar STX - AKG K702 - Sennheiser HD650.
Portable Audio: FiiO X3II - Audiofly AF140 - Etymotic ER4s - Fidue A83.