I wouldn't know...maybe it's because I have the basic Atmos setup in my home (5.1.2) but the comparison with the 5.1 mix wasn't absolutely "night and day"..I mean, you could tell the difference but it wasn't mind-blowing that is..just my opinion.
After spending some time with the Atmos mix, I finally tried out the 5.1, and I think it's actually more gripping. (Plus, the on-screen content when you choose "Play Album"--rather than "Select Track"--from 5.1 is a lot more entertaining. I can't figure out why the disc author didn't make that available when listening in Atmos.)