I wasnt at CEDIA, But

In a couple of webcasts recapping the CEDIA event they talked about straight down vs angled atmos implementation.

Straight down caused hot spots directly under the speakers in the listening room and dead spots on the further side away. Central seating was the exception obviously.

The concensus was the best ATMOS demo at the show was the Golden Ear setup, by Sandy Gross. (Founder of Polk, Definitive tech and now Golden Ear.) considered even better than Dolby's own! laugh In a recent HTGeeks podcast he explained why all speakers need to be angled towards the MLP slightly to create a uniform soundfield, Specifically ATMOS setups. He goes into some detail about the choices made in their demo room.

It seems the best final arrangement is a blend of science and artful placement. Fodder for us to scrutinize until ATMOS is properly vetted in homes.

Here is the vid: