I just watched Megamind 3D (7.1), The Secret Life of Pets (Atmos) and Upside Down 3D (5.1).
The Secret Life of Pets was the most disappointing sound wise. Despite the Atmos label, I actually went over and listened to my top middle side heights and they were DEAD during large segments. I mean nothing. No ambience, music, nothing. Bed surrounds were highly active. This comes down to poor mixing and nothing else as far as I can see. The problem seems to be some of these mixing guys have no idea WTF they're doing with Atmos, IMO. Too many soundtracks are all over the place.
Now by comparison, Megamind was AWESOME with Neural X. The bed soundtracks were clearly well defined to begin with (sounds all over the place all of the time including loads way behind me which often seems ignored on Atmos soundtracks for some unknown reason). Lots of overhead sounds, mixed pans and music overhead. It was better than the average Atmos or X soundtrack, IMO. Neural X is simply awesome with the overhead stuff.
Next was Upside Down (a weird movie if there ever was one with dual-gravity worlds, etc. etc.) and as you might imagine, that would imply TONS of things "should" be on the ceiling at points where the two worlds collide (in an office building no less) and despite being in 5.1 and you'd think that it couldn't get voices, explosions, etc. in the right position but they WERE! It didn't matter what the sound was, Neural X just seemed to "know" when it was happening in the other world on the ceiling. It was incredible, really. These weren't just birds, helicopters, etc., but voices, explosions, you name it (normal office sounds even) and the movie was in TrueHD/Dolby Digital, not even DTS (I forced Neural X). I'm more and more impressed by Neural X. It can turn canned tuna into a gourmet meal.
Overall, I'm actually starting to wonder if it wouldn't be better to watch the more disappointing Atmos soundtracks in Neural X. It might do a LOT better than poor film mixing engineers that are afraid to put things up top.