Just picked it up used, $475, and all I can say is wow!Can't say as I have tons of experience to draw from for a review, but I'll give a few thoughts...
First, the clarity is astounding. There is no boom, no mud, and no "extra" teenage car stereo bass.
Second, the extension is incredible, since I've never owned an audiophile quality sub. I'm already hearing content in movies and music that wasn't there before.
Its going to be a long road ahead of dialing it in to blend it with the rest of my system, and I'm still waiting on a cable from monoprice so I can place it where I want, but so far I'm blown away. Thanks to all who weighed in on my various threads and helped me with my decision!