You wont find any data recovery software that does a more thorough scan than that, even though it was written in 2004 or so and has been barely modified since. I spent years writing it, in C, so it ended up highly optimized. In forensics mode it scans a drive byte-by-byte, and it assumes each byte is the start of a file of the 100 or so filetypes that it supports, and it maintains that assumption until it is proven to be false as it goes deeper into that file's data. That way it really shouldn't miss anything. It also transparently UUDecodes, unzips, and otherwise decodes data on the fly as to extract file contents under as many conditions as possible. It uses linked lists to maintain its memory of what files are where until it dumps out its buffer as output files, and it uses binary searches and threads to speed up. All in all it's about 1000 lines of code, though I really don't think that anyone would ever be able to read it except for me.
I recently noticed that if you run it over your iTunes Music folder it'll extract and output the media that is contained inside your M4P ("MPEG 4 protected audio") files, and output it as unprotected MP3's. So it effectively strips all of the DRM off of all your media in seconds. Even if you didn't purchase that media (say your friend sent it to you) and couldn't play it before. That was not intentional. You can see that effect in this app: https://itunes.apple.com/app/file-extractor/id1129674765 which is the same codebase, but it is being applied to used space (files) instead of free space.