Hmm. . . well I guess I'll reply to my own questions. I am now using the DuoDive with two Sony HXR-MC50 cameras and the OLED display. The electronics allow one total access to the menus on both cameras at the same time, though most of the time I set them up separately before locking them inside. Also, I have figured out a better way to register the two cameras using Really Right Stuff mounts than is provided by the included cheese plate alone. The cameras can be set to 3 interaxial positions from 2.5 inches (orthogonal) to 3.5 inches. Anyone contemplating this housing should communicate with Werner Bloos to find out what cameras currently work with it. Because of space restrictions and, most importantly, recent changes in Sony's AV/LANC firmware, not all Sony products work. You need to be sure you can output the video and input the control either over the same cable or separate ones.
I have also added some much needed exterior stick-on bumpers to protect the housing and light mounts on the wing. Most important, WEIGHT needs to be added because, as I suspected in my posts above, the housing is actually about 5 POUNDS POSITIVE; hence it needs six pounds of added weight to make it manageable underwater. (I still wonder what Eric did about this in his tests.) I asked Werner for a solution, but have not as yet received a reply. My solution is to add 3 pounds of lead on either end of the wing using a couple of XS Scuba "quick attach" weight pockets. They are attached with velcro and easily removable for transport. They take standard hard or soft 3-pound weights, so no extra weight needs to be added to your luggage. They also provide abrasion protection to the ends of the wing. They should be placed slightly forward to provide perfect horizontal balance and stability. The solution is rather elegant, I don't mind saying.
Eventually I intend to write a complete review, but in the meantime, if anyone would like more detail feel free to write me.
Chet