I think Amie and Ian Colquhoun (the Axiom first family) run two VP150's - one above and one below their FP screen.

My sense, like Nick's, is that having the center channel as close as possible to both the vertical and horizontal planes of your mains is best. Having it on the bottom shelf would run some risk of reflections and reinforcement from the floor, which might not be a good thing.

But, you know, the only way to really find out about your ears in your room is to test out both scenarios.

bibere usque ad hilaritatem