I too applaud the work of MJFF, but I wouldn't judge a charity purely by its percentage of revenues used to fund research.

In addition to research, a PD charity can usefully spend money on support.

As a first step, I would look at the percentage of revenue spent on expenses. But this only looks at inputs: not all pounds spent on PwP are equal.

Regarding the number of PD charities, there probably are too many, but I see diversity as useful. For instance, one charity for research and another for support gives donors a choice as to where their money goes.

John