I have the 14-24, 17-35 and the 24-70. My favorite (of all my lenses) is the 14-24. It is really sharp at 14, better in fact then Nikon's 14mm f/2.8 prime. I have the 17-35 for those occasions where I want to use filters (ND or CP mostly). With an FX camera the 14-24 provides an opportunity for lots of creative use of perspective. However, I can see where the distortion might be a problem with people if you aren't careful. Since the wide lens will enhance the sense of distance between near and far objects, shooting at an angle where the entire subject is not on the same plane relative to the camera can result in distorted features.
In my opinion, the 14-24 is best used for enhancing perspective. Having looked at your photos, I'd say that if you want to continue doing what you have been but just want to replace your D200 with an FX body, then the 17-35 might be the better choice. On the other hand if you want to push your creative capacity and play with more perspective then the 14-24 is the way to go. For more traditional work the 24-70 is absolutely unbeatable.
The 16-35 is a great lens too and some feel it is sharper than the 17-35. However you do give up a stop of speed and it has more DoF wide open.
Given the price of the 14-24 it might make sense to rent one before you buy it. I love mine, but it sounds like you have pretty specific and critical application.
