Setting Up Atmos for Home Theater and Future Proofing

Hi All,

We are doing some renovations, and I'm looking to make some improvements to my family room / theater set-up.  I have a series of questions, but the questions to some depend on the answers to others.  So to start:

For setting up Atmos or DTS:X, I'm between going with either Atmos-enabled (upward-firing) speakers for both front and rear, or heights for both front and rear (near top of ceiling, being angled downward slightly, sort of like the Klipsch RP-140SA or SVS prime elevation speakers).  The ceiling is a flat ceiling, about 8'10" tall.

I've read that Atmos and DTS:X can work with both types of install - so anyone have experience with which is better? My receiver can handle both. (It currently handles either 2 front heights or two front Atmos, but I'm trying to future-proof a bit.)  Some people seem to prefer one over the other.   Depending on the person, some people think upward-firing are almost as good as in-ceilings, while others think they are awful and that slightly-angled heights are the way to go. So, thoughts?

Also, my next question or two may be clarified if I can post a quick sketch of a room layout - I'm new to this forum, so I'm not sure if I can post an image.  Is there a way?

Thanks for any help!