Yes, he really is a gentleman. When I first saw the lessons I thought we'd get a few as a taster then be required to sign up for a course with fees etc. Glad I was wrong there.
He is just pushing 70 years of age and was a teacher until the late 80s when he began to concentrate on recording and performing. Most of his recordings were played on instruments (both French and Italian) with full three voice musette, and he is also prone to shove the accordion aside and start singing.
Believe it or not I'm not really into his playing style, but these videos show that he is an excellent teacher. He often tells you that there may be another way to play certain things, and in my opinion that is one of his qualities. He doesn't force you to do things to a rigid regime, and respects the fact that the CBA can be played with different fingering.
This reinforces my belief that CBA methods are really only a grounding to get you started so you don't end up with your fingers all over the place, especially on a 5 row. What you ultimately do with it is only limited by your own ability and knowledge of the keyboard. When I bought my first accordion, which was a CBA, one of the shop staff asked me what I intended to achieve with it. My answer to him was "I just want to play it". It took me several years to consider all of the arguments regarding thumb use, fingering systems, whether the couplers should be on the back or front, what was the best treble button size, the relative qualities of B vs C system, etc. etc. etc. I just wanted to play tunes on the accordion I had bought, although because of all the tittle tattle regarding the right and wrong ways it was a long time before I felt confident with the playing style I eventually ended up with.
If I had a teacher like Jean-Yves, I probably wouldn't have the time to post on here, as I reckon I'd have at least made semi-pro. Video lessons and pdf files arrived too late for me, but I hope younger players take advantage of everything they can to make themselves better musicians.