Oly 3040 and PT-10 since October 2001. No special lenses or external strobe yet. I was thinking about it, then I bought a drysuit instead.
I like the small size and relative simplicity without a strobe, but I will eventually buy one as I could use more light sometimes. And I would like to get rid of the sparklies on some shots.
I have done about 120 dives with this setup so far. I am very pleased with it, though I have never used any other u/w camera so I can't really compare.
Deepest dive with it 35m, rated 30m. Sometimes I wonder if the plastic case really will survive, but it always has so far. My only complaint is that the macro mode button sometimes does not engage when I am at 30m. This only happens once in a while, but it always works if I keep trying it.
I find a set of 1700 mA-hr NiMH batteries lasts 1 1/2 dives with the flash on high and the screen on. I have not yet figured out how to change batteries underwater, so I change them each surface interval, whether I think they are low or not.
I have only ever had a fogging problem if I let the camera warm up in the sun before the dive. I am careful to keep it out of the sun and I find I don't need the package of dessicant. This may not be true in a more humid location.
I almost always take it with me because I KNOW that I will miss the photo of a lifetime if I don't bring it.
I find I am seeing vastly more of the smaller ocean life because I am always looking for something to photograph.