Not sure if my experience counts to what you are interested in, but I've been diving a Nauticam NA-7D housing with a Canon 7D (Mark I) for some time now. I only have the 60mm macro lens and port, but I love it. In our turbid water macro photography is usually all you get.
I'm using Ikelite DS125 strobes (2) and a Sola 1200 as focus/video light. It's a nice package.
The one thing I wasn't thrilled about is you only get manual flash. However, once I adapted it's not a big problem. I run ISO 200, 1/250 speed and keep it on F11 for the first shot, which is usually OK. I'll adjust the aperature accordingly after that. It's pretty easy to use all the buttons underwater, and we dive cold water with drysuits and the big blue drygloves.
The video is OK, but you do have to switch from "M" to "P" or you will chase settings forever. As it is, there's no tracking autofocus such as in the point and shoot cameras, and auto focus is quite limited. In the end I made a focus gear for the 60mm lens that works pretty well. It will work better once I get the hang of it.
Here's a very short video taken last Sunday. It's not great, but then remember two things: a) I'm using a macro lens, so very limited field of view, and b) dogfish sharks are quick and rather shy.
I did color correct the raw video footage as well.
But - I absolutely LOVE the macro photos I get from this camera. I can get a better macro from 12-14 inches than my point-and-shoot at 3, and when I get close, it's so much fun.
