Jonathan,
From the bench tests I have seen there is some difference of opinion on comparative resolution of film versus CCD. One test - for instance - puts a 6 Mpx DSLR at 80% resolution of ISO100 film. Yet another (reputable) test demonstrated 35mm ISO100 film scanned with a Nikon 4000ED actually outresolves a 16 Mpx 1Ds mk2! So your observation is about midway between these and I don't think your being unreasonable with your observations
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It appears one area that digital has surged ahead is in high ISO images - for instance the full size sample ISO1600 images from the 5D is simply amazing. Even with my 'lowly' 300D I am able to image stars down to 16th magnitude with a normal 50mm lens, 1 hour exposure from suburban Brisbane.
Terry