Thorax is a bit longer than Dan would tie it, and he'd usually use a bit more hackle in the front to push more water, but a very nice tie, as always. As an aside, it is very much in vogue these days to use a 60 degree jig hook like the Eagle Claw 413 for Whistler's.
Not sure if you've seen his take on the pattern, but you can find it here:
http://www.danblanton.com/spswhistler.html