I feel that the 14-24 can produce excellent images on the D800.
The 14-24 is not going to be very good in the F2.8 to F 4 range in the lower corners, but I felt it was still very good at infinity. From F5.6 to F7.1 the lower corners start to get usable and then from F8 to F11 outstanding. The hyperfocal at F8 appears to be around 10 feet to infinity. (my infinity distance was approx 400 yards away, ranging to just over 10 feet). I had hoped that the 14-24 would hold the lower corners in the F2.8 to F3.5 range for night work, when at infinity, but it's just not possible. For that matter I have only found one lens from Nikon or any others that really looks that good at F2.8 to F3.5 in the extreme corners on a D800. This would be the 24mm 1.4 as it can do OK, but still not to the level I had hoped for.
The Zeiss 21mm I worked with out performed the 14-24 in the extreme upper corners at 21mm but the out performance was not enough that I wanted to run out and get in line for the Zeiss. The same Zeiss 21mm was not that good in the lower corners at infinity until at least F10. For me CA on both lenses was about the same depending on the lighting. The amount of CA on the Zeiss was a bit of a surprise, but both lenses correct in LR very easily. (Still mainly using LR for D800 stuff).
Net to me, the 14-24 can produce some amazingly detailed, sharp images if you use it in aperture ranges that it seems to prefer. Color and contrast look very good. I would try one. It seems that with all lenses there is sample variation and I settled on the 3rd 14-24 I used.
My only issues, it's big and heavy and the Zeiss is much smaller and lighter, but it gives you 14mm which I love to use. Filters are cumbersome but there are workable solutions for both ND and CLPL. Flare can be a real issue also.
I hope to show some pics soon but right now I can barely get to the internet as I took a hard lightening hit to my studio. Sitll working to bring up all my machines and see if I have any data at all. Hope to show so examples later, however I am not a big fan of images downrezed for the internet and would prefer to show a full size 100% image, which is not possible via a link, but I hope to post some shots in my Dropbox public folder later.
Everyone's mileage will vary.
Paul