Long wall or short wall?


I know there are many threads regarding speaker placement and room acoustics. I am considering re-modeling a room to be a dedicated listening room first with a HT as a secondary use. The room will be 16' x 25' (golden ratio) and I will do room treatments as needed. Currently I am in a room that is 14'x 22' vaulted ceiling and my Wilson WP's sound better on the long wall , better imaging with a wider sound stage. When on the short wall, they sound more congested (if that makes sense ) the bass may be stronger but even with acoustic panels all around the room, they just don't sound as "open" and wide as they do on the short wall.

Ironically, there are two audio retailers that I have purchased from over the years, and one is all short wall placement, and another is very convicted to speakers on the long wall. I would of course try for myself but, I ask because as I design the new room, the built in acoustic treatments will need to be specific to where the speakers are located. So is anyone has specific experience with both and can offer a comparison .
Thank you
vdosc