...It seems to me that there is more distortion with the 12-24...
There are two types of distortion. One is a result of how the lens is angled to the subject. The other is in the lens optics itself. The 12-24 is not a perfect lens optically. The 14-24 is known to be on another level.
There is software to correct specifically for the inherent flaws in the optics of specific lenses at specific focal lenghts like DxO optics and PTLens http://epaperpress.com/ptlens/ For landscape this nice, for those that do a lot of architectural work then this software is very useful. Of course the 14-24 might be even better. I cannot comment on the 12-24 vs the 17-35 for architectural captures. The best solution for those specializing this this type of work is probably 14-24 + FX. But, as I tried to show with everything above, shooting with DX does not mean you can't do this as well.
Albert J Valentino Nikonian Moderator Emeritus Vantage Point Images Mastery of Composition is the Key to Great Photography