Just adding my two cents... (feel free to give me back the change)
Andi is right about the button alignment... although the buttons for the shutter speed, the aperture, and the trigger all worked with no problems, I was rarely able to access many of the other camera features, such as adjusting focal points or hitting the Info button from the histogram.
These issues were a little annoying, but I shrugged them off as a typical prototype thing that had to be dealt with. I don't know if the base tray needs to be adjusted or if the rubber nipples on the buttons themselves are simply not reaching the camera, which is what I suspect.
I had no problems with leaks whatsoever... I probably would have stopped shooting completely had I even seen a droplet of water inside the housing.
I also had no problems with scratches on any of the ports (I had three, the macro port, the 4 inch dome, and the 8 inch dome). The 4 inch dome has a rubber protective cover, but the other two ports do not. I am hoping one will be made for the 8 inch dome.
The biggest outstanding issue from my perspective is the buttons issue... I was told it had been resolved, but I have heard from a few people who say their production models suffered from the same problem. Of those, some people have had some frustrations getting their housings shipped back in time for a pending trip.
I am taking my housing to the Honduras in two weeks and when I get back I will send the housing back to Korea and let everyone know how things are going. My main issue is getting the buttons to all function.
As for customer service problems, I have had very good response when working with the owner of the company and am not sure who out there is saying they had problems or what those problems were. It would be nice if someone could comment publically on any situations if possible.... I think that would be a benefit for everyone concerned and would eliminate these issues of "someone" saying "something" happened. (Just my thoughts...)
I just re-read my review and am seeing some things I should have discussed more in depth or clarified... I'll have to work on that.
The only two people I know of for sure who have used these underwater are Eric (with DigiDeep) and myself. Has anyone else used a Jonah underwater with a Nikon or Canon?