Hey Brian, I believe they were talking about a strictly stereo plus sub environment. I don't see where anyone said that adding a center would or would not change things for him. That would be a whole other discussion. A good discussion, but different.
Not upgraded from a stereo environment, but from 3.1 to 3.1. My last center channel was a VP150. Sub is EP350. EDIT: My prior point, but, unstressed, was if I experienced a change by swapping the VP150 for a VP160, then it would stand to reason that you would also hear a similar change by swapping the M22's for M60's.
Sonically, 80hz sounds the best, but I like the added bass effect sometimes by lowering it to 50hz. 2 examples is the movie Tron Legacy, and the concert Police Certifiable.
Pioneer with it's 6 storage areas for sound doesn't store the crossover point. You have to choose one of the 6 and a crossover. Too bad they didn't make it easy to have, say, #1 as 80hz, and #2 as 50hz, etc. The way it is, you have to dig several layers deep in the menus just to find and change it.