Well, the difference in form-factor is pretty significant. Jason's room is dedicated to his theatre.
Luc, don't underestimate just how deep the M80's are physically. By the time you move them out from the wall a bit, the effective size of your room is going to be diminished by about a meter in that direction. Same thing with their position relative to the side walls.
If you have other furniture in that room, the M80's could disrupt your aesthetic.
Honestly, given the size of your room and the size of the M80's, I'd just stick with the M22's. Perhaps experiment with their placement a bit. See if you can borrow another sub from a shop or a friend to see if that makes a big difference for you.
