Some of the DC2's had overheating issues and were revised so be careful. In terms of how they compare against the vanilla versions its the same GPU core. I believe that the DC2's are voltage locked but some1 can correct be if I am wrong. The reference cards are louder in terms of the fans. Reference cards can basically overclock just as well as the factory overclocked cards they just have issues with the loud fans and some aftermarket cards have better cooling solutions. If your looking for cards that are compatible with water cooling blacks reference is the way to go to ensure maximum compatibility.
Edited by switchblade - 2/9/13 at 9:20pm