We use them for home theater so we got 3 for an L-C-R application. The slim profile is what originally attracted us to them. They are mounted on the wall next to our plasma, and they blend in nicely.
As for sound, they are great. I have no complaints. We use them to feed music to the house during parties as well and it works great. Loudness is also going to be a function of your source and amplification, but I am sure most systems would be sufficient. You can get away without a subwoofer, but why would you do that?
I originally found them at Magnolia (in Best Buy), but ended up buying them from another place at a significant discount.