This movie was a career-ender for almost everyone involved (Xander Berkeley did alright), and it's no wonder why. I'm astounded this movie was actually in theatres, because the way it's written, directed and acted feels so much like that of a bad TV movie.
First, the writing. It falls victim to the biopic curse, of having nothing much to say, and no real cohesive plot. Scenes just go from one to another, and after Christina goes to the convent the basic thing that the first two thirds had, conflict, is thrown out the window. Although the conflict it did have was so one-note that it quickly becomes boring, and I don't need to mention the hilariously bad dialogue, as the other commenters have pointed it out. The characters are one-note, and the movie only tris to make them two-dimensional at the very end, when it's basically pointless. Their maid serves almost no role in the first two acts (if there is any structure), and then is treated like some important parental figure at the end. And Joan is just a crazy bitch for almost the whole movie, until Christina returns and it decides not to be a movie anymore, when they start making her somewhat sympathetic, but then she
leaves them out of her will, which destroys it all. I think what they were trying to do was have Christina try to forgive her mother, only to have Joan let her down, but it doesn't work because it comes out of nowhere, and there is no indication to the audience that this is happening. For this to work, we'd have to get Christina's perspective, but we don't until the very end, when her emotional response is obvious anyways.
There's not much to say about the direction. It's just very flat. The whole movie is just so boring, and the camerawork does not help at all.
The fun part, though, is the acting. Over-the-top performances are not alien to Faye Dunaway, but this is her peak. She doesn't really give Crawford any nuance, though the script obviously doesn't help. But she's just so entertaining. The infamous "wire hangers" scene is so poorly executed all-around that she comes out looking like a cartoon character. The kid actors are really bad, but the actress that plays adult Christina does her job. One actor that stood out to me was the fella that played Joan's lawyer/lover, Greg. He's so wooden that it's hysterical. I was so disappointed when he left the picture, because it was always a joy to hear his delivery. Everyone else is pretty much just mediocre.
I'd recommend it if there were more "so-bad-it's-good" scenes, but as a fan of movies that are so bad they're good, skip it. It's dull as hell.