Replacing Everest in our labs is AIDA64. This new testing suite is from the core development team from Lavalys and continues that tradition. The guys have thrown in better support for multithreaded CPUs as well as full 64 bit support. We use this to test memory and HDDs for now, but may find ourselves opening this up to other areas of the motherboard.
At stock both ASRock Z68 boards perform near identical to each other with very little separating them. The only time we see a bit of change is when we look at the overclocked results and that's of course because the Extreme4 is offering us a slightly higher overclock.