I recently got an Aperion subwoofer, S-8APR, to combine with the rest of my system (Paradigm Titans, CC-170, Atoms, and PDR-12 subwoofer). I think these are all excellent sounding speakers, I'm so happy with them!
I have a relatively small living room, so in particular I got the Aperion to reduce the room acoustic issues when only having one sub. Also I set them so that the Aperion handles the higher bass, and the Paradigm the lower ones. I went for the Aperion instead of another Paradigm because I liked the fact that it has those passive radiators on the sides, also it was very well reviewed by DVD ETC., particularly for music (actually it was ranked higher than the PDR-12), and most importantly, listening to it I liked very much it's fast and punchy sound, excellent little sub.
[This message has been edited by rsaavedr (edited May 02, 2003).]