I'm quite new to this digital SLR stuff, and just bought a DA 50-200 zoom. I thought I'd try comparing it to my old Super-Takumar 1:2.8/105 (which I feel is a great lens). After some muddling around with a wobbly tripod (even with a gallon of paint hung from it), I finally got things rigid enough to satisfy me. Even figured out how to get the mirror to lock up for the exposure! Now lets see if I can add a link to the resulting composite photo.
http://pages.cthome.net/maren/Composite_105.JPG
Interestingly, neither lens seems to show significant dropoff in resolution at full aperture. Also, the DA resolution seems as good at that of the Super-Takumar, with perhaps better contrast.
This is a first attempt at this, so if I'm doing something wrong please be gentle. I'll try to do it better next time. I intend to compare the same DA lens at 180mm with an old Primotar 1:3.5/180 and see how they match up. Then perhaps do some 50mm.