As a suggestion to improve the File Finder in v4.x I'd recommend it display secure checksums such as MD5/SHA-1 or something along those lines because "generically" showing matching filesizes doesn't give me any confidence whatsoever that a file is actually a real duplicate and thus I'd never once use the tool for that reason. Displaying matching/mis-matching secure checksums would give the needed confidence to actually consider using the tool.
Yeah this would be good. I'm a bit wary about using duplicate finders as I've heard sometimes things that aren't duplicates appear to be duplicates in the program so something that could help you make sure they where exactly the same files would be great. On the name, I was confused at first when I saw File Finder as it sounds like a general search tool rather than a duplicate finder.
I'll also add my other suggestion here to be able to filter results, or only search, by file type/extension. At the moment it gives me a lengthy list, mostly files which are filetypes that shouldn't be messed with and I have no interest in. Now as a disorganised type being able to ONLY find image files or ONLY video files etc would be far more useful, rather than having to hunt through a list of obscure system/program related files
Please add header click sorting of the results - not many people want to be given C:\$Recycle.Bin\etc at the top of the list - I might want the list to start with the largest space waster ;
Please add a summary of the results showing the total sizes of all :-
the duplicates that are currently checked for deletion;
the duplicates that COULD be checked for deletion.