I could not pass on the Pixtreme. Many of our dives a photographer diver is provided. For a fee, you buy a high quality video of your dive to bring home.
I can not see spending $500 or more for a few of my own photos.... But for $90 (at Newegg) with a free 256K SD card, I could not pass.
It is small enough to fit in my BC pocket, and I tie a long string to my BC so I wouldn't drop it. I have not used it with a flash, but 2 AAA batteries lasted me about 2 dives, and about 50 photos. Supposedly the provided rechargeble last longer, but I have not found a charger for it.
Without flash, the camera is too slow, so 1 out of ever 2 photos are too blurry. The delayed snap to picture time is at least 1/10 of a second, so half of the time, your object is already out of the frame. Of the 50 photos, about 20 were keepers - just enough to make memory of the trip, but certainly not enough to publish.
With good light - the photos were excellent. They do have a flash kit, and macro lenses. I believe the whole package with flash, macro, extensions, cost less than $500.
The best thing I like about the pixtreme is that I tuck it in my BC, and pull it out only when I want to. It doesn't get in the way of boarding and unboarding of dive boats, I don't need help getting it back on board in rough sea, and if I broke it, it is less than $100 to replace.