I'll go with Mary. DR would whitewash things, trying to keep it classy. I mean which book made a bigger splash? Dreamgirl or Secrets Of a Sparrow? Dreamgirl and it's because Mary wrote about the good, the bad and the ugly, whereas DR's book sounded like a cheesy self-help story. Now it can be argued that since the public on average sees DR as a temperamental diva-- no matter what she writes, people will project their bias
onto it. Is it fair? No, maybe not, but people get behind an underdog, which was how it was with Dreamgirl. On the other hand, I don't think many people care anymore about Diana Ross or the Supremes, so I doubt a movie will ever be made at this point.