The M80 vs a VP150 as a center is no contest. The M80 is much more dynamic and lively than the VP150. If I could run an M80 center or even an M60, I would do it in a heartbeat.
Since I have dual VP150 (the one below firing straight, belly-level and the one above slightly pointing downwards about a foot or so above the head), I would now tend to vote on the dispersion of dual-centers over a single M80. Sounds is still very directionnal to satisfy dialog and character movements, but evenly distributed accross all my seating positions.
