are you staying DX for a while,, or have any plans to moving to FX,, like say a used D700? or a D600 as their prices continue to fall (I predict sales in 6 months of around 1700 dollars!)..
If staying DX for a while,, then any of the lens will do that get you to the wide angle, Hence why I bought the 10-20 almost 10 years ago, more choices now. Any professional stores around that you can look at in person? It might just be the feel of the lens that makes the decision for you.
As far as quality, the Nikkor consumer lens are not that much different anymore from Sigma or Tokina, so, my vote would be for whichever lens has the highest optical quality. Whichever lens you buy at this price point, needs to be treated gently.
If you do go FX,, then even a 20 mm prime gives a nice wide angle.
I will say that dollar for dollar, at 14-15 mm, cheaper to go DX. ultra wide on FX cameras are not cheap.