I have also been using my new Nauticam GH3 housing for a week of diving with the GH3 and Panasonic LUMIX G X Vario 12-35mm F2.8 lense in the Nauticam 6' Wide Angle Port.
I am very happy with the housing. I really recommend this setup.
Hey Starfish - I am very interested in your input on this setup.
I have been waiting for the right time to buy a new camera for both topside/general travel use and underwater photo/video, and have been very tempted by this setup. How do you feel this lens works for underwater work? The Panny 12-35 seems like the optimal "first lens" for topside/travel, but I've been wondering how suitable it is for underwater. It sounds like you're quite satisfied - do you have any photos/video you can post? I'd welcome any additional feedback you have about this gear.