Fortunately the M40s are Boston Cherry, which I already have. If they were Mansfield Beech or Maple I would probably have to think about buying them. Whew
I never had a chance to directly compare M3s and M40s, but in terms of "forwardness" we previously concluded that M50s were a bit more forward than M3s and a bit less forward than M60s. The M40s have the same speaker complement and crossover as M3 (AFAIK) so should sound pretty much the same except at the low end.
I wouldn't expect M40s to play more loudly than M22s -- their real forte IMO is as "pure music speakers" at moderate volumes.
