I am quoting from my previous experience - I used to have a Klipsch rig and progressively found the center channel to be the weakest link when I tried with RC10, 25 and C2.

When I changed it to an Axiom rig, I noticed that VP150 sounded significantly better than the 100. (yes I know its subjective). I am currently setting up a second system with M2 as a center paired with M60s for L/R. Will let you know my impressions sometime at the end of next month.