Took the housing to Australia to dive with Mike Ball on the Great Barrier Reef and the Coral Sea. The camera and housing performed well. No leaks, no condensation, no overheating or mechanical problems of any kind. The images it produced were excellent to about 40 feet or so. As others have pointed out is holding the camera steady and white balance in the ever changing underwater conditions are the biggest issues.
I would definitely add a wide angle lens from the gitgo. The cameras lens is not wide enough and a wide angle would make camera shake less obvious. I made the mistake of shooting in the 30 frame "progressive" mode. I think that 60i is the way to go. The progressive mode seems to soften the image somewhat and it adds to the perception of unwanted camera movement.
The camera and housing float (canon warns in the operators manual not to use the housing as a "flotation device", semi-seriously I assume) so I used a gorilla pod and a 2 pound ankle weight wrapped around the pod to get negative and to steady things out a bit. The ankle weight was pink and drew a few laughs from other divers, they could not however resist watching the video.
I had not been diving in 18 years so my rusty skills likely contributed to some of the shaky clips. Also there were high winds which took the surge much deeper than usual. At times it felt like trying to shoot while being laundered on "gentle cycle". All in all the camera and housing are well worth the price. The photographer who works the boat is considering a hi-def camera, the sony ex-1 and housing, total cost $20,000.00. To get halfway there at less than one tenth the price is just a heck of a deal.
If you ever get a chance to dive with Mike Ball do not hesitate. It is a first rate operation in every way and an unforgettable experience.