Felisek made the call and is hopefully happy with it. Enjoy shooting!
Please allow me to add my two cents, though: I was the proud owner of a Tokina 11-16 for many years and took a lot of great shots with it. A few months ago, I switched to Tokina's 12-28 and am even happier, both for the wider range and the better sharpness. ColorFoto, a German magazine that in my view does the best job of any German or English speaking photo mag I am aware of, because of its thorough and repetitive test process, gave the 11-16 (versions I or II scored the same) an IQ score of 50.5 points. Nikon's 10-24 received 54.5. Tokina's 12-28 got 61. (All of these tested on D7100. ) The only wide angle lens to beat this was the Nikon 14-24, with an impressive 68.5 points (but a weight and price point that take it out for me).
My experience is exactly the same: the Tokina 12-28 beats the 11-16 very clearly in image quality (and convenience - it stays on the camera a lot longer), so I assume it also beats the Nikon 10-24 by a significant margin.
As far as that "10mm beats 12mm" argument goes, even at 11mm I went for panoramas every so often, using Microsoft's fantastic (and free) ICE software to stitch them together, because the lens wasn't nearly wide enough. In situations where a 12mm focal length is not enough, just overlap multiple shots and you won't ever find yourself limited by width.