Hi there, Melomann;
I'm kinda in the same situation you are: I'm currently using three M3s across the front, and having really good luck with an M3 as center. I'll be getting a new receiver soon with 7.1 capabilities and am planning on using four M3s in back as well.-So if it dosen't work, we'll both fail together-lol.
Alan, of course did it again-good advice at a bad time-I'm sitting at twelve feet and change in a 3900 cu.ft. room.(which is why I'm getting a new receiver and towers) So while I'm happy with the M3 as a center today, I do know that the M3 does occasionaly sound a little strained if pushed a Bit Too Hard in this new room. I never found that to be the case in the old house with a more average sized listening room. So Alans' advice on the VP150 is something I'll be taking very seriously-Thank you Alan!
But Yes: I agree that the M3 makes a very good center-there are lots of us using bookshelfs as centers with good results.
