I have and use the Tokina 11-16 F2.8 and it's a delightful lens in many ways. Not being much of a landscape shooter, I consider this my "party lens" in the sense that it's great for indoor spaces..gives a good sense of a space instead of the the cramped feel one might capture with less wide lenses.
Furthermore it's that much more light-sensitive and gives a slightly more shallow depth of field.
If I have any criticisms of this lens, it's how prone it is to flares in sunlight..pretty large hard-to-remove large crescents.
However, the same may be the case of the 12-24 - I do not know.
Regardless, if used carefully, it can produce very pleasing results.
Due to the good focal range readouts on the lens, you can go hyper focal, and thereby reduce the minimum focus distance for close-up shots.
Good luck with your decisions!