I have it, and it's a great lens. From what I've heard, it's not something you'd want to shoot lens resolution charts with, but i've never had an issue with that, in fact it's sharp enough it seems to almost out resolve my 4x5 lenses... You definitely want to get an 8mm or 16mm extension to use with it, it brings the focus in and gives you a nice range to work with for portraits.

But we can talk all day about supposed goodness, here's a few images instead: http://www.flickr.com/search/?ss=2&w...q=150mm&m=text