Bought this based purely on the review, and I'm not disappointed. The speaker is slightly larger than a golf ball, but it's loud enough to fill the room with sound. I'll definitely be getting more of these to see how they work when they're daisy-chained.
The speaker operates in two modes - open and closed. Closed it sounds about right for a speaker of its size - reasonable sound quality, no bass whatsoever. Open it, and the bass suddenly makes itself known. It's not going to make your windows vibrate, but it's definitely noticable - as others have said, it has enough bass to try and move across whatever surface you put it on.
It comes with a small felt bag to carry it in, and a charger cable that splits into audio and USB adapters, so it can play your PC speakers (or another source) while charging. The charger connection is standard mini-USB, so you can live without the specialist cable if you lose it.
My only small complaint is that the integrated cable isn't very long (as in, it's about 3 inches long!), so if you don't want the speaker right next to the source, or if you want to spread out multiple speakers, you'll need an extension lead.