I believe what this does show is that, like you have stated, CCF is kind of an afterthought for most. It actually matters or it is a waste of money. It needs to be as soft as possible, much like pillow stuffing (but that isn't good for car use and is why we do use CCF).
Too stiff, and it gets to be pointless (or even worse) as you get to the point where you would have been better off just hanging the MLV by itself with no decoupler.
It also shows a pretty wide range of CCF products from 970hz to 1550hz. No where near as good as some, but still a fairly wide range.
This also is similar to CLD tile choice matters. Some are good, some aren't.
MLV is the same as not many actually make this.
3m ACOUSTIC thinsulate works well and I used this quite a bit in my truck, but it must be the acoustic thinsulate.