Earlier today I moved all speakers out of my 4,200 cu.ft. main room and listened to just the M2s and M5 bookshelves with my 3 subs crossed over at 80Hz. Try as I might, I could not hear a difference between the M2s and M5s. The only time I could hear a difference was with Audyssey off - the M2s don't need Audyssey. The M5s benefit a bit. (The M100s benefit a lot). At times I thought the M2s image better but really, I cannot be sure. I do know the M2s are less fussy with placement. I pushed both from very quiet to very loud (103 dBC at 12 feet away).

If you're not going to use a sub in a space larger than 800 cu.ft., M5 is the way to go. With a sub or small room, save your money and space and buy M2.

As for on-walls, they are nothing more than wife-pleasers. If you want an emotionally rewarding performance, floor-standers or bookshelves are the way to go.

My buddies and I are simply stunned with the M2. Last night, one of my buddies who is very familiar with all my speakers, thought the M100s were on. It was the M5s. He didn't believe it until he checked for himself.

House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated