Digital BW, The Print

So  Which reviewers to believe?  I guess you'd just have to test them
yourself first.

There were a lot of complaints on the scanner list that the nikon 4000
didn't hold the negatives perfectly flat, and were slightly out of focus
at the edges. I used both nikon and canon 2720 DPI scanners, and Found
that was true with the less expensive nikon scanner. The edges were NOT
as sharp as the center. I understand you can get a glass filmholder that
would alleviate this problem with the Nikon 4000.

I've seen other equipment reviewed by many different reviewers, and they
drew opposite conclusions. So the best advice would be to test before
you buy.  Someone else on the list today said the canon 4000 was TOO
sharp. Imagine being too sharp. I don't think I could imagine that. 

Perhaps you get better scans with black and white negatives with the
nikon. Maybe canon is better if you scan color negatives and use their
FARE software. 

Test before you buy, if you can, or else buy from a company that will
refund your money if not satisfied: B&H, Calumet, Camera World

Jerry