Well i am sort of split on this issue.
When it comes to macro i like a really tight lens and i am going to shoot the 105mm 9 times out of 10. If the object i am shooting is too big then i go for designs or something. Macro, definitely fixed length.
WA on the other hand...i do like a versatile zoom lens. 17-35 or 12-24. What i thought was a fantastic lens on a film camera was the 24-50mm, what a fantastic lens for sharks as well as sooo many other things.
I shot the 15mm on a Nikonos almost exclusively for about 2000 dives, then i finally housed my N90 and had the 18-35. i had often wished for a zoom to get such things as people shots, sea fan shots, and shark shots at Blue Corner, Palau as i went there 3 or 4 times a week. However, i usually chose the 15mm (this was before the housed camera) because i had to get a slide show of guests together. Therefore my shark shots looked like minnows instead of sharks. At the end of the week when the slideshow was done i would go for the 28mm and get a few shark shots.
At the moment i shoot with the 12-24 and i like it a lot. Most of the time i shoot at 12mm but having that option to zoom is a definite plus for me. (but then again sometimes the blur on the edges at 12mm when close up ruins a shot completely...) Which of course leads me to want the 10.5mm
Grrrrr.... so many lenses, so little money...
If anyone wants to start a "purchase the 10.5mm lens for Mike" fund please let me know
M