An update on my subwoofer search. Future Shop had a one-day sale on the Velodyne DLS-5000R for $600, so I picked one up to see how it sounds. The sound is fine and I really liked having a remote to change volume, etc. However, it's a big black box. If I were putting it in a home theatre setup where everything was black I wouldn't have any problems with that. However, it's in the living room where I have the Boston Cherry M60s and the rest of the furniture is maple done in a "coffee" coloured stain, so it didn't do anything for the décor.
I took it back for a refund and ordered an EP 350. That will match the M60s and should be less visually obtrusive. It would be nice to have a speaker that goes lower, but I'm not going to obsess over that (although I realize the point of these forums is to obsess over details just like that).
A good torture album for subwoofers is Dupre's Symphony in G Minor for Organ and Orchestra, played by Michael Murphy on the organ in the Royal Albert Hall. The organ has a 64' pipe and there are some places where I'm sure it drops below 20 Hz.
Anyhow, I'll let you know how the EP350 does when it arrives.