Across the board we see memory performance is very similar between all motherboards here.
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.
AIDA64 gives us a better representation of memory performance with the Z68 offering that strong memory performance like the P67 chipset. The only time we again see the ASRock boards separated is when we throw overclocking performance into the mix.