I have one, and unless you have a room with no openings, or at least doors on the openings they don't work right, as they rely on sound waves bouncing off the walls to make the surround properly. With openings you lose sound out the openings, so it's not bouncing where it's supposed to.
I ended up buying a low profile sub that fits under my couch, so I have wires running around the outside of the room for that, and then I bought some wireless rear speakers. Works great now, but I was a little dissapointed with it on it's own.
*edit* I have this model, which isn't exactly the same as the sound bars you are looking at, but same idea:
http://www.soundmatters.com/fullstagehd/