Are you temp limited on overclocks? If yes get a better block. The XT is best, I don't care what Gila keeps saying. For ease of use and proven temp results, the XT. You want the Uber, best by temps and hard core proven? Stay with the best HK 3.0, be careful there is up to 4 now different ones to buy.
But ONLY if your temp limited on overclocks.