I use the DX-8000. I recently spent 7 days aboard the Sailing Vessel Juliet in the Turks and shot over 500 pics and over an hour of u/w video. I am using the Sea & Sea housing and arm with the YS-110 strobe and fish eye lens. (Note the fisheye lens says DX-5000, but its the same housing.) I am also using the SanDisk 2Gb Extreme 3 memory card. It has a 20Mb/sec read/write capability.
There are a few things you need to know about this setup.
I am using rechargeable AA batteries to power the camera. There is a lithium option, but the AA batteries, using flash on every picture, are good for over 100 shots. Get the highest Ah batteries you can find. I am using Duracell 2650mAh. I have seen 3000mAh advertised on the Internet. That is insane, 3 Amps! The strobe uses 4 AA batteries. When I was on the Juliet, I had my cabion setup with my laptop, external 120Gb hard disk, and external SD card reader. I transferred the photos after every dive. I never had a single problem with the housing or the firing of the strobe.
If you are going to use RAW format, be prepared for long wait times underwater. I am using Fine for the most part. I found that at the highest resolution, it writes a huge file (13Mb).
I took all my pictures to Walgreens when I got home from my Turks trip, and all the pictures came out great. You can crop them, and they still come out great.
Overall, I am very pleased with the camera. Tomorrow I am leaving for Pensacola, and I am diving on the Oriskany on Sunday. I plan on taking the Sea & Sea down on both dives. If you are interested, I can post some pics from this camera from the Turks and from my dives this weekend.
Hope this helps.