I have the system setup, and saw some demos and 1 movie.
Atmos sources can sound very nice. Also they can sound very bad, as they can mix anything in the sky.

DSU seems nice indeed, i did watch one movie and some clips. Could not find faults yet.
It sounds more around you (immersive is a often used word) than the normal 5.1 or 7.1

Also did the Auro3d upgrade. It is however either 12 channels for Atmos, or 11 channels for Auro3d. Combined you can have only 5.1.4 Atmos with Auro3d 10.1
With 7.1 base system you can have Atmos 7.1.4 with auro3d 7.1, or do even use wide channels, and do Atmos 9.1.2 with Auro3d 9.1

Sold all M equipment