I've got one and really like it for what it does. It is a lot of fun and you get a lot of interested comments and questions. I've tended to stick to higher iso films, but i've seen lots of examples of people using 100 iso on sunny days. When ever i take it out i've always had dull weather which is probably why my results haven't been that impressive. I have used it with 800iso film right down to quite low light conditions with some success.
A couple of things that I would point out are that you really need something interesting to fill the frame. The lens is quite wide and with a 360 spin, you can end up with a lot of empty negative and a boring photo. With this in mind, it is really great for group photos. Stick it in the middle of a table for friends and spin and it is perfect.
I would also say that it is not a good camera if you are a vain photographer. I really don't give a damn about these things, but i've taken the most awful self-portraits with this camera. They usually consist of me trying to lean away from the camera inducing several double chins, with a concerned grimace on my face. It is not a natural camera to use so I look worried every time it spins.