Yes, THE CHARLIE'S ANGELS STORY has some pretty good -- if slightly schlocky -- impersonations, so you can almost believe while you're watching it that it's almost them. And the narrative doesn't wander too far from what is "known" about the stars and the things that happened.
But the DYNASTY: THE MAKING OF A GUILTY PLEASURE overtly had nothing to do with the actors who were being portrayed. John Forsythe was presented as a bombastic fool with whom even Blake Carrington couldn't compete (the way Joan likes to falsely portray him), Linda Evans is presented as a slightly-rednecky cookie-baking ditz, while Joan Collins herself is played as a higher-class breed of actress than she actually is.
Only the portrait of Esther Shapiro as a grasping, hustling operator quite works (the Shapiros' rustic cottage is the secret star of the show, much as is Harry Hamlin's house in MAKING LOVE). And Aaron Spelling's fey Hollywood player is similar in both movies albeit a bit inferior in THE GUILTY PLEASURE program.
What was weird(est) about the DYNASTY one was that it aired on the same network, ABC, which broadcast the actual show in the '80s -- something not considered industry protocol at the time in 2005. The lead cast publicly came out against the film, with Joan calling the ABC brass "lowlifes."