I purchased this lens when it first came out and never looked back. Great lens, nice and sharp, pretty uniform distortion and very wide on DX.
I struggled choosing between this lens and the Tokina 11-16mm 2.8 and it all came down to speed vs focal range. I find it very useful to be able to go all the way to 24mm, and frequently only bring this lens when heading out with my camera because of it.
I don't pixel peep, but the IQ has always looked great to me.
As a side note, it also works on full frame or film from about 15mm onwards.