Hi! I tried it, the first two months was actually trying to find their place/position. In my room that is the optimal distance. If they are closer the music is too congested, doesn't really breath. Further away I loose to focus.
It maybe helps, that the side walls are really have the distance (even in this position), so the speaker stands really free. How knows.
Matter of fact I am wondering every time I see Avantgarde horns close to each other how can they sound good :)
I'm surprised you are able to get great sound with the Nanos that far apart. Neither mine, nor my friend's, work well if there is more than 9 feet between their inner corners. I would suggest you try moving them closer together - you might not know what you've been missing. Avantgarde also recommends it. Setting the speakers up in the room correctly is much more important than room treatments, in my experience. Good luck!
Carboncopy, Very nice system. I totally agree with your take on the Quad 21L. They are phenomenal speakers. I have been using mine for 9 years and don't have the itch to upgrade them. How big is your room and how far have you placed them from the rear and back wall? Also your decision to go with the same cables throughout the system will reap huge benefits. Welcome to audiogon and enjoy your music.