9 out of 10 points and recommendedGreat build, super sharp, great macro performanceSlow autofocus, tripod collar
This is the best lens in my bag on many counts. It's sharp as a tack and consistently takes incredible pictures. I also have the much cheaper, but also well rated Sigma 70-300 APO 4-5.6 and there is no comparison in the pictures from the two lens.reviewed March 18th, 2010 (purchased for $650)
Like all lens, this one won't make you a great photographer, but it certainly does provide a photographer with the quality glass necessary to take exceptional pictures.
While not a true macro lens I especially love the close ups this lens takes, they are remarkable. The primary subject will be tack sharp and the background will have that truly beautiful dreamy bokeh.
A downside of the lens is that autofocus is not fast and at times the lens will hunt for focus. I love being a Pentax shooter, but on my K10, this isn't a great lens in that regard. The K10 is a bit slow to begin with and this lens magnifies that. I hope it becomes less of an issue when I upgrade to the K-7 shortly.
My only other complaint is that while the tripod collar is well made, it's not quick on and off and the screw can cross thread even when I'm being careful.
I would probably buy this lens again, but after owning it for 9 months, would also take a close look at the Sigma 70-200 2.8 just because focus is stronger on that model. However, the Sigma doesn't have the great macro performance this lens does, so I would probably end up at the same place all over again because this really is a great lens.