I've heard good things about the Dickason Titanic sub, too. I think 2x6spds has one; perhaps he will chime in. I believe Parts Express is in the process of updating this model to the new driver series.
Now, they call it the Titanic MKIII Subwoofer Kit
Lots of people have Adire Shiva subs, too, which can be had in about that same price range. Like sages of this board have long commented, the challenge is not to get a "good one", the challenge is to get a good one at a good price. I've yet to hear any sub cheaper than ~$350 that I thought would be worth the money saved. It's not "cheaper" if you become dissatisfied in a short period and have to replace it.
Another issue for me is the form-factor. God knows theories abound on the topic, but I don't subscribe to the notion that it matters *sonically* if the sub is down-firing or front-firing. However, it matters very much to me on a livability standpoint; I'm only entertaining the notion of a down-firing sub in my child- and dog-infested abode. The less fur- and grape-juice-attracting grill cloth I have to maintain, the better.
