It could be that the pictures I have held in my hands done with film
scanners were done by people who did not know how to use their dedicated
film scanners.
However, I have done some tests with my Epson 2450 of some of my negatives
that I have printed in a darkroom and MY results are very good. My ultimate
test will be of course to show the scanned negs to another photographer or a
gallery owner and see if the results of my flatbed scanner passes the
muster.
Before I got my Epson2450 at Goodwill ($20.00 ! ! !) I did a workaround with
a scanner with no provision for a transparency adapter. Here is a link to a
page showing what I did:
http://www.tom-elliott-photography.com/hp-scanner.html
So that being the case, IMHO if you know your software YES flatbeds do rival
and surpass the film scanners.