I can echo a lot of what Sterling and Jim said in their writeups yesterday - the GH3 is definitely my favorite mirrorless camera to date as well. I really like the 60 frames per second, and coupled with the Olympus 60mm lens and the DP4 monitor, it is a macro beast. The datarate is high enough to get excellent quality with a little room to push it in post, and the workflow with the MOV files it creates is very easy. On a recent trip to Bonaire with Reef Photo, I took the GH3 out for a spin and shot this:
Demo reel shot with Panasonic GH3 in Nauticam NA-GH3 housing. Using Panasonic 8mm and Olympus 60mm lenses, Keldan and FIX lights. Shot at 60, 30 and 24 fps.