LXi and KevinH
The only problem I had with running the unmodded + upgraded BIOS setup was that the system was incredibly unstable, and considering that every one of our benchmarks with the exception of cachemem and Quake III Arena were run under Windows 2000, I wouldn't have been able to paint a very accurate performance picture with the unmodded + upgraded BIOS setup.
Scientifically speaking, yes, it would make more sense to have done an unmodded + upgraded BIOS setup however without a stable platform to run the benchmarks on that wasn't a possibility unfortunately.
Another thing you'll want to take into consideration is that OCWorkBench has reported that the original person that submitted the R126/R127 modification did so after finding that the new BIOS did not improve performance.
Basically from the standpoint of the consumer, the conclusions should not change, the MSI K7T266 Pro and the KT266 in general are not mature enough platforms at this point in time to consider. When they do become more mature we (and I'm sure other sites will too) will provide recommendations accordingly, but until then we just can't.
Take care and thanks for the feedback guys, it really does help us make this an even better place for you all.
Anand