The listening area in my apartment was 12x20. My M80s were about 6-7 feet apart and I sat 6-7 feet from the screen. I noticed a huge improvement in sound quality when I upgraded from a VP150 to an M80 as a center speaker. For that matter prior to the upgrade I had turned my center channel off and ran a phantom center with my M80 mains.
It sounds from your first post that you are also turning your center channel off at least sometimes because you also find the M80 sound better especially for music. If that’s the case then IMO it is worth the upgrade. I’m not sure how close Steve said he sits to his speakers but if it isn’t close then you might want to wait on someone posting comments on how it sounds close up or placed fairly close to the mains, but from a sound quality standpoint it should be as much an improvement as I got with my M80 center.
