Interesting back and forth on soundstage depth, thanks fellas. As I told Phil this past weekend, I want the most even sound in the room. Configuration is of second importance although livability can't be completely eliminated.
Phil values living space more, so I expect to have the speakers out a little further than he would normally prefer. I'll post a picture of the setup this weekend once the speakers are unboxed and into the initial position.
What I can say is the "L" shape of the room clearly has echo/reverb from the adjoining space so I am completely onboard with trying the long wall first which has much more symmetry. There will be a fireplace in the middle and some paned glass on the rear wall, but there are solutions for that in due time.
Also interesting is my Kiwi friend
@Pallen just setup the Gibbon Xs in a 14'x15' room successfully with no bass issues. He originally thought about downsizing to the Super Nines, but isn't sure now.