I had asked a similar question over on
www.getdpi.com.
I have personally tried the 16-35 F4 nikkor and 14-24 F2.8 nikkor. After all I had read about the 14-24 being such a great lens
wide open, the results I obtained were not that good on a D800. With the 14-24 at 14mm I found that I had to be at around F8 before I was able to get
a really good image that was sharp corner to corner. At F2.8 the corners are not only soft but show a bit of smearing. I was able
to try 3 different 14-24's and all pretty much returned the same results. CA is a slight problem but easily correctable in LR.
With the lens at F 6.3 and up it can really perform and as I mentioned at around F8 the images were very good. Lloyd Chambers mentions
a problem with focus shift with the 14-24 at around F5.6. I am hoping that he will do an update on the 14-24 based on a D800.
As for the 16-35, I have not really been able to use it but one or two times. At 16mm there is a good bit of distortion but you can mount
filters on it.
Ultra wide on the D800 is definitely a test for good glass.
Paul