Check out the vids "Zilla posted on the first page. they're about 30 minutes each, but solid info. The Dolby PDF isn't really 60 pages, but it does have the key info about ideal angles.
I think this is the biggest part in Atmos is getting good coverage. I suspect, for the people that complain about it most, they are not properly set up. In fact the guy gives an example in one of the vids with pink noise off axis from a ceiling Speaker: we know what should happen if we think about it for a second, and this guy puts it out there to hear. By the time you get say three seats off axis of that Speaker, all the highs are gone and you just have the lows.
Ideally I would have my Atmos Speakers Higher, I think, to get the appropriate angles, and they would be narrower if I could do ceiling mounts, bringing them into the room about 2' or so.
Regardless...
Eager to hear Bill and Zilla's thoughts.