Actually, I ran M2i mains in my HT for quite a while and was VERY happy with them. IMO it all depends on the room size -- my system was in one end of a 13x23 room and was just great. I did swap between M60s and M2s as mains and found the M2s were fine for "about 2/3 of the room" but weren't quite up to filling the whole 13x23 room with loud, clear sound.

I ended up donating the cheap tower surrounds to my brother-in-laws new system so now have the M60s as mains and M2s as surrounds, but IMO the M2s are surprisingly good as mains if the room isn't too big.

Enjoy your new system.

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8