audiofan,
I have a Sony receiver as well...I have the M60's with a VP150 center and M22's as rears.
I am still experimenting with my system but speakers set to small and everything set to 90 sounds excellent.
Set the front crossover to 60 if you want a bit more bass...
I will have to set my center and rears to 120 and see how that sounds...
It really comes down to what you like best. I know that if I am using the sub with my M60's for music (setting to small) I leave it set to 90...Sub off - 60.
M60's set to large for vinyl or CD direct...
Used to have a set of Sony HTIB speakers and they sounded best with the crossover set to 120 or higher...for all...
WhatFurrer