Hi Andrew - sweet looking system! Love the colour of those speakers. Glad to see that you know the value of a well treated room; too many folks have invested >$100K in gear and then do nothing to treat the room acoustically - damn shame.
Other than the obvious RPG Skylines, what other treatments are you using? It looks like you have something on the entire front wall and side walls - thin absorption perhaps? How have you treated your back wall and ceiling? Do you use an acoustical measurement tool to see what your ears hear and to compare before and after treatment effects?
Again, great system. Enjoy.