RObert Budding
D'oh!
Personally I don't like vignetting and neither do I like the blue cast of the Nikkor -- to me the Skopar wins this hands down. But that Canon in the last post is also pretty wonderful (I think Winogrand used one of these for his Public Relations project).
I'm not inclined to judge color cast based on scans. It's possible that these were done in 'auto' mode. Much better to look at the slides on a light table. Or to verify that the poster used a color-calibrated work flow.