I have one. AMAZING piece of equipment. Takes horrible underwater still though. but then again that wasn't the main intent of the camera. recordings are crisp, clean, and the sound is decent. Underwater filming could use a different lens, but rumor is that GoPro has one in the works.
All around, worth the $250. I was happy with it within seconds of watching my first clip.
Edit: Also depends on what your primary use will be. Some work better than others