Every MOCF here with the same cpu (4133 c12 IMC) and same kit of ram performs the same. I have five MOCF some early ES but most retail. I only have one M8I so can't test on Asus but at least in my case binning boards has not been required for maximizing memory clocks.
I would be down to limit to 100.00 seems to be the only way to keep things perfectly fair. Both Asrock and Asus are over the limit on the first step past 100 bclk can't say for other vendors as I have not tested them. The only thing I have thought about is splitting the bclk steps in half i.e. making them more granular, so instead of 100.0625 the first step would be 100.03125 which should keep things legitimately under 5003 mhz but I am not sure how easy this would be to implement.
Also I think not having to freeze ram to get a top score has kinda caused this recent influx of killer lcc submissions. In pre B die days you actually had to freeze memory (and usually cpu) to get a proper sub and now AIO cooler and a fan is all you need to get a competitive result just the way it is.
Your XP has to be seriously busted for it to be slower than Windows 7. Even a vanilla XP with just the basic tweaks (LSC, maxmem, waza) will be much faster than stock W7. No execute must be off in the bios and just to be safe in boot.ini as well.
Can you do me a favor and pull out a stick of memory and or swapping the order of the modules?
On an early revision of the M, I had to sometimes let the battery sit out for almost 10 minutes along with removing the 24 pin and clearing the CMOS but this has since been fixed on retail boards with the latest bios.
Pull the CMOS battery out for a few minutes then you should be good to go. Then reflash MEI it might be corrupted, seems to happen sometimes when pushing memory.