I agree entirely with the Nicks duet. She's only used at the end and when her voice came in, I was found it to be totally jarring. I'm not sure if it's where it is in the overall mix or the way it was recorded, but, to me, she sounded different than usual. When they sing together at the end, the harmonies were fine, but on her own, it was disturbing, for lack of a better word. And I like Stevie Nicks a whole lot so I was disappointed.
Don sings "Here Comes Those Tears" great, but I'm not thrilled with the arrangement. The acoustic guitar that drives it early on feels like it's going too fast. I think Jackson's version will always be the definitive one, in my opinion.