I don't see any reason for the majority of people to RMA the board because the fact is, it does what it's supposed to do. However, if this problem is widespread (in that it affects most RIIIE boards), I will not buy another Asus product. That would mean that buying the top of the line in no way guarantees or even gives you a decent chance at getting a good board as there is no way any sort of binning has occurred.

In fact, it seems that these boards have a particularly bad IOH. I have never heard of this issue before the RIIIE. It's not present on my Gigabyte board at all, and that was 2 levels below the top when it came out (UD5 and Extreme above it).

The reason I say most users won't need to return it is that maybe 10% of the people that buy this board will ever push over 220 BCLK.