I went from a larger bookshelf speaker to M80's initially and the step up was considerable. I did move up a few notches to the LFR1100 that was simply mind blowing. Also upgraded from a joke of a center channel to the VP180. That speaker does it all and then some.

I have a pair of the EP500's paired with these speakers in a room that is 16x17x9'.

I would agree with your thought of buying the M100's and then deciding on the sub upgrade. I also have found with my own experience that two subs did sound better over my whole room than just a single one. The M100's do give off a remarkable amount of lower frequency bass and if you were looking just for music, for many it is more than enough. (The LFR's are like the M100's with an extra set of speakers in the rear).

The sound stage and imaging will be a set up from your M22's and you will be perma-smile happy with the setup.

Anthem: AVM60, Fosi DAC-Q5
Axiom: ADA1500, LFR1100 Actiive, QS8, EP500, M3, M3comp, M5