One of the distinguishing characteristics of so many Peterson shapes is the large ratio of the diameter of the shank to the diameter of the bowl, creating an almost tubular effect as one transitions into the other. The "338" shape is a particularly good example of that stylistic idea-- the diameter of the shank is almost as large as the bowl's, giving the impression that the bowl is a bent pipe (pipe in the plumbing sense, that is) rather than a combination of shank and bowl. To my eye, it creates a particularly rugged and masculine composition. That's furthered in this case by the rustication of the Donegal Rocky series.
-- Sykes Wilford