Add options to select duplicate criteria: size, content, name, date

Two files are duplicates only if they have same content, so that has to be the final test to ensure they are really duplicates, but it takes a lot of time to compare all files. Options to narrow down which files to search can be size, date, name, extension or combinations of these. I prefer first to find all files with same size, then compare the content of those with same size. Date/name/extension could be used to further narrow down the search. Use something like this:
First: choose drive/directory to include (always exclude system), then allow option to narrow down search by date/name/extension
Second: sort the list on file size.
Third: compare content byte by byte.