Could we have a user defined column?
I'm thinking now of using it for md5sum (but could be something else) which could be used after sorting files to find duplicates.
With fdupes it's a bit harder to select.

try Komparator4

Thanks for the "Komparator" suggestion. I didn't know about that. Looks very good having a checksum.

BTW I can't see the "[tick]Accept this answer" button.