Hsu or yamaha sub?

I've been looking for a reasonably priced sub to match with my Thiel CS.5's. I don't want to spend a lot of money, yet I don't want to sacrifice quality.
The VTF-2 and Yst-800 seem to be the two hot subs for $500 or less.
Has anyone matched these to a quality pair of speakers for a stereo setup? How did they sound? Any suggestions would be helpful.
I plan on connecting this sub to my preamp out on my Arcam Alpha9.
I would get the HSU. Another decent new under $500 subwoofer is the Monitor Audio ASW-110.

Used you might find a REL Q100E or Stratus II for a little over $500.

I have both a hsu and a yamaha. I don't have the yst800, but the reviews are really good on it. The yamahas I've heard indeed sound good. In the end, I would have to go with the Hsu subs. Really, really deep bass. The only fault I can really find is that they can be overdriven easily.Idon't think you could go wrong with either. Hope this Helps.
You cannot possibly go wrong with the hsu. I have used it favorably against subs three times the cost. I have not used the Yamaha, but I am sure you will like the Hsu. good luck.
Hello. I have never used the Yamaha YST-800 but I have used their older YST-500. I also have owned the HSU VTF-2. I personally liked the older YST-500 better than the HSU. I didn't really care for the HSU personally. I am not sure what all the clamor is about with this sub. If anyone thinks it competes against QUALITY subs costing 2-3 times more they are out of their minds. I tried for about 2-3weeks straight to get this grand performance out of the HSU and it just didn't happen. For me anyway. I think you should try the Yamaha YST-800. There seem to be a ton of HSU subs on the used market and you hardly ever see a YST-800. I wonder why?????? Oh yeah, the HSU is U-G-L-Y (IMHO)too.
I sold a Velodyn HGS 12 and bought a HSU enough said!
Hsu has lots of low bass energy for the $$$. Great for HT. Though I'd probably get something else for music.
No comparison. Yamaha comes out way on top. You get what you pay for with Active, variable bypass subs. And this one has a full function remote. Very subdued yet, you will see pictures on your wall crooked after watching a good war movie.
Hsu are good subs but the Yamaha YST-SW800/1500 are way more tight, controlled and musical. I updated from Hsu to an M&K and then finaly to the Yamaha YST-SW800, I own a pair of them.