nkonor...
Good point on the 3.5's midrange. I find that the 3.6's, for lack of a better term, seem to over-emphasize the thick of the midrange while the 3.5's offered a more "spacious" replication? I also notice a more evident, but typically correct feel for the bass - particularly at the conservative volume level I listen at. Nothing I've tried to put a finger on rings as a coloration of the sound, rather a considerably larger speaker's difference compared to a smaller one's. The 3.5's may have measured a little deeper with the bass, but I feel it more with the 3.6's.
As I've said in the past, "what's a few hertz here or there amongst friends?"
Are you using a sub with the Avalons?