Maybe an H/K owner could comment on the global bass thing, and VMAX modes. 100Hz crossover is OK as a 1st approximation. Depending on your speakers, sub, room acoustics, etc, somewhat lower might be better.

I've got M60/VP150/QS8 and Hsu VTF-3R and use a 80Hz crossover for most music and HT. I have to use a 120Hz crossover for SACD, since it's fixed by the player. I can't tell much difference.

Good, well-mixed albums sound great and poorly mixed albums sound bad. With good speakers like Axiom it's just amazing how quickly you're limited by the mix and master quality of the source material.