Jay . , Jan 04, 2002; 12:23 a.m.
The first version of this lens (3-cam, pull-out hood, 1990) was made for Leica by Sigma and used Sigma's design and glass in what I refer to as a "Leica-lookalike" mount. It was released along with the R-E body and for a time it was sold as a kit. The performance of the lens is on a level with any good Japanese zoom of 10 years ago, and indeed a Sigma lens of the same optical quality could be bought in other brand mounts for a fraction of the R version.
The second and current version of this lens (ROM, screw-on reversible hood) is optically almost identical but no longer made by Sigma. In fact, the current mount is the exact same one used for the 35-70/4.
I had a 1st-version for a couple of weeks, and shot a test roll through the second version. The sharpness and contrast were equal to the 28-70/3.5-4.5 AF Nikkor I owned, but the "Leica" lens showed significantly more distortion at both ends. Though it has been reported in a popular Leica "lens tester"'s book that performance of the 2nd version is better [only] at 28mm, I'm afraid I just couldn't see it.
I have read from a few owners of this lens that they are very happy with it, and I don't dispute that. I was happy with my 28-70/3.5-4.5 AF Nikkor. But I expect more from Leica, and the 35-70/4 delivers. I've also read reports from owners who say the 28-70 has "that Leica look". From the outside, yes it does. On film, IMO no it doesn't. To me it is overpriced for what it is.