I use the 170's for surrounds and like them ALOT. I have a difficult room as far as surround placement goes (TV and mains in one corner and my position diagonally in the other). I had to experiment with a few different surrrond locations to get the results I wanted. In my room, when watching movies, I found that angling the speaker towards the back wall helped fill the sound effects in a bit in my seating position. Although I haven't experimented with multi-polar speakers in my room I would tend to think that they might be a little less finicky in their placement. As a side note; on my 3803 receiver I noticed there is an accomodation to switch between two sets of surround speakers so you could have a multi-polar design for movie surround duty and a direct-radiating set for multi-channel music.

Randy