I moved from M22s to M60s, and though I wouldn't characterize that as a "step up," I WILL say that I found I preferred the M60s + sub, to the M22s + sub. Though It would be impossible for me to predict, you might feel the same. You have a pretty good sized room and might find the M60s do a little better job filling it. If you are not using a sub with the M22s, you WILL notice a big difference in the bass response of the M60s.

Jack

"People generally quarrel because they cannot argue." - G. K. Chesterton