The round M3's do just fine for ceiling applications. It's not like there's that much data that gets sent to them, so worrying about having the best full-range speaker over your head just doesn't matter that much. I have two rows, and they are 4' apart, with my single row of seats placed equidistant to both rows of speakers. Even with them being this close together, I can detect the directional movement of objects over my head. I use M3 on walls for my side and rear surround channels - all as close to ear level as I could get them. Good Atmos tracks sound pretty amazing. I definitely get the whole "bubble" of sound thing Atmos touts.
