I agree - full range is probably better. Cost isn't my main consideration, but getting it as good as possible without breaking the bank would be ideal. As far as size, I'm fine with either the M3 or M5HP for the surrounds. I think I might go with them M5HP for the surround.

What about the heights? I'm thinking M3 just to reduce the footprint. Does anyone think the M5HP would be too big to put on the ceiling?

And for both - should we mount them with tweeter in or out? I'm thinking out to provide as much "width" as possible.

Regarding listening to music in surround - currently, I actually prefer listening to music using Dolby Prologic II Music mode, which directs quite a bit of the ambience to the surrounds. I find it fully envelops me in the music and opens up the soundstage. I don't find it negatively affects the front soundstage or imaging. But I'm not that accomplished or critical of a listener. So in this regard, the M5HPs would likely be better for the bed layer.

But I've never heard the Dolby Atmos Surround mixer. And my receiver eschews Dolby Prologic II modes (Music, Height) for the DSU. Anyone have thoughts on this?

So I'm thinking M5HPs for the 4 bed layer surrounds. Still need to figure out the heights? Are M5HPs too big? I'm assuming they would still work with the ceiling full metal brackets.