Hi Bill,
It's not that M22's image better than the M3's, but the M2 and M22 have a more 'transparent' sound - no mid bass hump.
My 1st vote is for 3 M22's across the front as your LCR, but since that's not an option I'd go with M22's L&R with M2 as your center. Note that I have the exact LCR setup you're considering - it took me 2 years to get to this setup after starting with the VP150 initially - I wish I had known about it from the beginning as you seem to be doing now.

Dan
On-Wall M5HP LCR, QS8 & EP500 in 7.1