Velodyne Vs. Hsu

I'm trying to slowly update my system. Currently I've B&W N805s as my main; which will eventually become rears as I aspire to be able to get some N802s as main speakers.
My system will be working as both two channel music as well as a HT sytem. I mostly listen to Rollings Stones/U2/Billy Idol (95.5-classic Rock in L.A) type music. I'm a fan of deep/tight bass (as opposed to getto blaster bass). I'm looking into quality used sub classifieds.
Thanks in advance for your input guys.
I will agree with Tim in regard to REL ST subwoofers. I own a Storm III that I use with a pair of B&W N803's. This is a musical subwoofer that is able to provide tuneful bass that integrates better than any other subwoofer that I have had in my system. An excellent choice, one that you will not regret.
Velodynes with servo control are great, but watch out for the earliest version of the HGS-10. Mine is the early version and is working great after 6 months, but a lot of people at Audioreview had major failures. The HGS-12 didn't have as many problems. The bigger Hsu seems to be a great sub (check out the Audio Critic review), but it's tall and tips over easily. It's hard to hide. My Velodyne is an 11" cube that goes anywhere. In a normal size room a HGS-10 is plenty. I listen mainly to baroque chamber orchestra,organ music and The Who. It's only down -4 dB at 20Hz at my listening position. 20Hz is clean without doubling;it knocks dust off the ceiling fan and cracks the walls.
At the price point of a Hsu I would choose it over a similarly priced Velodyne. But for more $$$ I would also get a REL.
At less than $1000 used you could get a Servo 15 from Paradigm. I am not sure why people don't embrace this sub as well as it should be. Unreal performance. Velodynes are good but VERY pricey. HSU subs perform well (TN1220) with their bigger amps but their build quality can sometimes be lacking.