Hey thanks for that link. I did not think there would be so much variation between copies of the same lenses. Since i am using a rollei with electronic shutter, I will probably eventually go with one of the Schneiders or Rodenstock lenses at this focal length. mark
I don't know how on point this is for your application, but this might be of some help. This guy has tested a lot of the current large format lenses (using film and an Air Force resolution chart) and he has published lp/mm resolution figures. He's tested two different copies of the APO Sironar-S lenses, as well as many other options. It looks like the Schneider APO Symmar is the best of the bunch, though they're all good. Check it out at:http://www.hevanet.com/cperez/testing.html
If you're looking to give it a whirl on something good but less expensive, I'm selling my Nikkor W 210mm f/5.6 for $300. I really like it (on 4x5) but I just got a similar focal length lens as a replacement.