Update -
OK, I hae had the Cygnus almost a month now. I think I have finally realized their placement in my room. In my 21 x 15 x 9 room, I have the Cygnus about 93 inches from the front wall into the room (tweeter face to front wall distance), about 41 inches from the sidewalls (middle of woofer to side wall) and tow-in is where each tweeter is aiming at my shoulder from my listening chair. The distance apart (tweeter to tweeter) is about 102 inches and the distance from the tweeters to my listening position is about 130 inches.
The sound continues to be amazing and impress. Never have I had a loudspeaker sound so liquid, smooth and rich, and yet have tremendous detail and realism. The bass is great and I continue to teeter between using a sub or not. I like it both when the sub is on and off. The ARC Ref 250's seem to be able to control the bass quite well in a room my size. Fast, punchy, extended and detailed.
The Rockport Cygnus is probably the best audio purchase I have ever made.