Here is a link to a series of studies on the topic:
http://www.audiocircle.com/index.php?topic=92856.0
The main conclusion seems to be that off-axis response is most important to people.
Steve N.
Excellent set of articles, written by the man himself, Floyd Toole.
I totally agree with your synopsis that the off-axis response is most important. Of course there isn't just one "off-axis response", as there are many off-axis angles, whereas there is pretty much just one on-axis angle. And not all off-axis angles are equal, as the perceptual effect of early reflections depends in part on their time delay and arrival angle. So imo the next step might be to start looking at different radiation pattern shapes, and how those different pattern shapes interact with the room.
