Great contribution, Bruno! Now just 487 more melodicas to go. Seriously, though, this really helps in the struggle to find the right language in terms of which to make comparisons and explain the differences among models.
In addition to that, though, given the extent to which your video brings out the difference in sound among these four primo models, it provides a basis for comparison of other models to these four “standards.” I just did this with my Suzuki MA-32, whose unusual sound has intrigued me. So I took it out and played along with the first category samples and the result was clear: the MA-32 has a “Clavietta” sound. That’s what’s special about it. It doesn’t sound just like the Clavietta, but it sounds much more like the Clavietta than it does like the Professional, the 44HP or the P-32D.