Well, I got $400 birthday money and $100 gift certificate for McBain Camera for my birthday. I fully intended on seeing if they had a Tokina 11-16mm and Sigma 10-20mm. They had only the Sigma. I did some comparisons between it and the Nikon 12-24mm and in the end spent the extra $350 to get the Nikon. I noticed a lot of barrel distortion and a definitely color change when attached to the D80. This lessened a lot on the D300 but was still there a bit. The Nikon was definitely the better lens though and in the end I justified spending the extra money on it.
It would be a nice day to go and take some pictures with it but it's REALLY windy today. In Alberta, wind kicks up sand, which isn't too good on lenses. Speaking of which I picked up a Kenko Pro1 Digital low profile UV filter for the lens as well.