Hi, cmdasia,
Well, I have an F100 and I think the differences in the features of the three you are considering are relatively small when it comes to using them underwater. I made my decision based on the housing I wanted.
I liked the Subal housing for the F100 and so I got the F100. So, I would like to answer your question in a roundabout manner: try out the various housings you are considering and see which one is the most comfortable and easiest to use. For me, the shutter release, the controls, and the handle were just a lot more confortable than any of the other housings. However, this is a matter of personal perference and not a comment on quality or reliability. However, I recommend that you try a variety of housings to see how they "feel" and if you have a preference based on "feel".
Once I settled on the housing, the camera was an easy choice: the bells and whistles on the F100 were too much to resist.
Another decision that you have to make is what lens(es) to get. I have three: a Micro Nikkor AF 60 D, a Nikkor AF 20 D, a Zoom AF 28-80 G. The latter require a different dome than the first lens. I would suggest that you start with the Micro Nikkor AF 60 D because it has enough range to do great macro photography along with decent wider angle shots. I have taken photos of wire coral gobies with this lens and on the same dive, a spotted eagle ray. However, if it had been a group of rays, that lens would not have been appropriate.
Hope this helps,
Scorpionfish
