IMO no speaker on the planet is suited for an environment with tile floors unless you have some other absorbtion (eg a rug, soft furniture, fat people etc...)
M2s are very neutral; M3s are just the tiniest bit "laid back" (midrange dip) but not as much as, for example, Paradigm Monitors.
I ran M2s as surrounds for a while and was very happy with them, particularly for music. I upgraded to QS8 surrounds which were significantly better for movies and IMO not *quite* as good for music.
What crossover frequency will you be using ?
