I tested an m5ow as a center last weekend between my 2 passive 1100s. I really didn't notice that much difference overall between the m3 and my 180 as far as off axis response. The 180HP puts out more sound but I felt like the m5 sounded more natural on dialogue on movies. I'm splitting hairs but it just seemed a little cleaner vs the 180. Honestly I think if I decided to run a AT screen I would go the m5 route. I've even considered going m5s as LCR and moving my passives to my dedicated stereo room.
On another note about the m5s, in stereo, I moved the tweeters from above ear, level, and below ear. The biggest difference to me was as I moved them lower the soundstage shrunk just a little each time but the imagining improved. I really enjoyed them more at ear level or slightly below.
