I can’t speak for the other editions, but I think changing the default MIME type from Catfish to Thunar in XFCE would better meet user expectations.
Whenever another application, e.g. Firefox, tries to open a directory to show a downloaded file then Catfish will open a blank window ready to search that directory. The user then has to search for the file which, if the file name is obscure or if organizing the directory was the intent, can’t be accomplished in Catfish easily.
After changing inode/directory in XFCE to Thunar, Firefox will then open the directory and also select the file they were looking for.
What do you think?