Good discussion. FWIW, saw Lee's RAD stuff a few years back. Turned out its equation matched my 96 stumpy paired with 60mm stem, that felt insanely good, really tightly. But at the end of the day, he's picked a random multiple to apply to rider height that seems to work especially well for the average height rider - he's either plucked this from his ass, or being generous its reverse correlated with some of his personal real world observations. Even allowing for the latter, it's a really weak theory to work from. The fact that Lee thinks your arms have a role in pumping, and sells an exercise machine based on that, probably gives all the context you need on his scientific rigour generally.
What RAD does say, which appears to be true and is a feature of modern Geo, is that having your CoG centred on in the bike and plenty of room to move it around that central space as needed, is a good thing. That's what makes me curious about the 'new' Geo; all that space to work 'in' the bike rather than moving about 'on' it as the trail changes/gets interesting.
