During the last month, I had a chance to shoot with two different pre-production samples of the DA 17-70mm f/4 SDM lens. Although these are not final production units, my sample images should give you a general indication of how the lens should perform. Note that unlike the 16-45, the 17-70 extends its physical length when zooming towards the long end of the focal length range.
In terms of handling, I found the zoom ring of the 17-70 to be nicely dampened and smooth when turning. There was no indication of zoom creep in either of my samples. I also found the manual focus action of this lens to be smooth and precise, especially when I tested shooting sample close-up subject matter that I've included later in this post.
The following series of images were all shot in RAW with a K20D and processed into jpegs for posting here using CS3 and Adobe Camera Raw with no adjustments. I've included photos to show the zoom range, casual walk-around images, and some close-ups. I've included a shot of one of my favorite photos by Harold Edgerton to give you a sense of the distortion we can expect at 17mm. Although I'm no measurebator, my feeling is that controlled lab tests will determine the degree of barrel distortion at 17mm is similar to the 16-45 and the Sigma 17-70.
I have another series of photos that I have not yet had time to process, but I'll try to post them in the next few days.