My first choice is direct radiating behind the listener (45 degrees off axis), but it sounds like that's not an option for you. Unfortunately, it wasn't an option for me either in my current room. I had to go with ceiling mounts directly above the listener and am using dipoles. I have listened to dipoles and direct radiating from the side mounted position and strongly prefer the dipoles in this configuration. The direct radiating sounds impressive the first time you listen to it--there's so much sound coming from the sides and you can pin point it's location. With really loud soundtracks--ones with race cars or jet planes flying around--it's a very neat effect. However, for most material it sounds very artificial. It doesn't really envelope the listener the way dipoles do--there's way too much sense of where the sound source is--and that's not really what you want for the surrounds.
Dipole surrounds Vs. Direct radiating
I'm building a system to be used for home theater and music. What are the pros/cons of using dipoles vs. direct radiating speakers for the surrounds? The room is 17 x 19 x 8.5 and surrounds will be wall mounted adjacent, not in front or behind, to the listening area.