Purchased this lens recently from the forum marketplace, and have been very pleased with it. Long enough for birding, but small enough to fit in a daypack for long hikes. Fine color and detail, especially when stopped down a bit. Here are a few samples, all taken with K20D, and only minor cropping for compositional purposes:
White Breasted Nuthatch on the side of a White Pine.
Hermit Thrush on a rotten stump:
Great Blue Heron watching the annoying photographer:
Male Eastern Bluebird on a Red Cedar branch:
and one more, a Female Eastern Bluebird on a fence post: