I have the HTS-10 in a very small living room. I got it from a work rewards program after initially getting a definitive technologies sub (from the same program-- only two available) which was atrocious beyond words.
Having sold the old Polk PSW subs a lifetime ago while employed by Circuit City, I wasn't expecting much. That is doubly true with the sub on my reference system being a DIRAC-controlled Rythmik, which I believe to be the best sub I've ever heard at any price, period.
I was quite shocked by how good this Polk is. It is not the Rythmik, but it is more than adequate for this little room, doesn't call attention to itself, and looks nice. It's a very notable step up from budget friendly subs, like the Dayton 10s I used to have. I wasn't expecting that.