You are true blue audio research. I stayed away from audio research because I didn't feel the tube preamp used with home theater made sense with all the tubes and replacing them frequently and having my usage tracked so carefully by the preamp make sense but the sound is probably pretty darn awesome.
Looks to be a very dark space. Do the hard surface floors impact sound in a bad way? Definitely a lot of wood on the walls. Have you thought about putting ceiling acoustic panels which I can't do because of all the plaster ceiling which would not work out very well.
Those main speakers are really pulled forward quite a bit do you notice that much of a difference or could they sit back a little but maybe that's good. I have a basement where the speakers are in the middle and they sound lovely.