Hey SEC FAN,
I just got my M40's yesterday and I couldn't be happier!
To be honest, I expected them to sound like my M3's only with the abiltiy to go a little lower in the bass area. Boy, was I wrong!
I had my M3's set-up with a crossover of 80Hz. When I hooked up the M40's, leaving the same freq. cut-off, bass had a lot more presence. I decided to set-up my M40's as "Large" speakers with the crossover set at 60Hz and they sound great. BTW, when I re-calibrated everything, I had to lower the mains by about a dB indicating to me the M40's are more sensitive than the M3's.
Anyway, I still have my JBL N24's as surrounds. I can't wait for the FULL METAL BRACKET to become available so I can put my M3's up as surrounds. The VP100 serves duty up-front. I watched Aliens3 last night and IMO the VP100 is a good match for the M40's and M3's. But I've never heard a VP150, so I can't tell you it won't sound better.