It sounds, from a glance, that maybe BMW should have invested some effort on a Spintron- sounds like it helps analyze harmonics of the entire engine.Can you imagine what those bearings would look like if xW-20 was used during track days?
I'll bet nobody running thinner oil than the specified 10W-60 sees any better bearing wear on stock bearings while keeping all other factors constant. Also, maybe guys are using 10W where it gets pretty cold and pushing the W rating to the limit or beyond, which doesn't help engine wear during very cold start-ups.
Ben Strader of EFI University has some videos of their LS engine on the Spintron at 11,000 RPM… and it lives!