I think for a fair comparison you need to listen to the speakers on the same axis and bandwidth limit the content. Take port out of the equation.
We dont hear frequencies equally from above, nor do pleasing sounds usually eminate from above in nature-especially music. Usually danger.
The goal of distributed audio is equal coverage, and almost always in mono. Not sure if that is your use.
I’ve been involved in a few projects and can say sound from above does not sound the same compared with in wall speakers on the listening axis. Definitive Di6.5r all around in an 5.2.2 Atmos install was one. Sound from above without the aid of subs sounds thin and extremely directional.
