It's hard to find in the article anything more than what already is on Photorec homesite since a number of years, the "Photorec step by step" page:

http://www.cgsecurity.org/wiki/PhotoRec_Step_By_Step

is actually more comprehensive.

Yeah, you're right. Their guide even has screenshots for each step, which I hadn't noticed before. Anyway, the purpose of the article was to increase awareness of those amazing tools. I find it surprising that many people are not aware they can recover their data without paying for a commercial application.

Well, then Photorec (which is in itself an excellent tool) is not the only one, personally I am particularly fond of a lesser known tool, DMDE, JFYI:

http://dmde.com/

which is provided - besides the licensed/commercial version - also in a free version with only minor limitations (and it exists for DOS, Linux and Windows).

Maybe the object of a next article?

TestDisk/Photorec is not just free, it is open source as well, and is available in most Linux distributions' repos. It may not be right for everyone, but it is my tool of choice.

Sure, but then the point is not about the "many people are not aware they can recover their data without paying for a commercial application".

Rest assured, and specifically I have used (besides Testdisk) both Photorec and DMDE extensively, that no tool is "perfect" and each tool may have some particular function that works where another tool doesn't, so when the game is "data recovery" the first rule is "throw (at the device) anything you can", beginning with one's tool of choice obviously, but without setting aside any other one.

Yes, have used both - TestDisk and PhotoRec (CentOS) extensively and both work like a charm.