CLOUD ATLAS is a peculiar and unique film. Although I enjoyed watching it, I think the narrative structure was so confusing that it made it almost impossible to appreciate, as I spent an awful lot of time trying to figure out what was going on. In addition, the stunt casting of having each actor play six roles was far more distracting than it was helpful. I don't think anyone ever postulated that when people reincarnate, they keep the same looks as their previous life. Seeing Halle Berry in whiteface and a man dressed as a woman were particularly interruptive to the flow of the film. Some of the makeup looked like rubber masks (although some of it was also outstanding).
I look forward to an extended cut on BluRay as it is likely that would answer a lot of my questions. I have not read the book, but I did notice in reviews that the book has a palindromic structure, in which each of the six stories begins in consecutive order but finishes backwards. (A mirror fugue, if you will, to keep the musical metaphor of the title piece, A Cloud Atlas Sextet.) I think this structure would have suited the film better, as all of the intercutting seemed forced, particularly at the end, where they felt the need to make all the stories climax together in an intercut frenzy. In fact this probably would have played better as a miniseries.
It's kind of hard to "spoil" the film with any plot reveals, but I did want to mention one bothersome moment. Someone shoots a dog. Both the dog and its owner are not integral to the story at all, and it's a particularly disturbing display of pointless violence. I'm sure the reason that it was placed in the script was to show what a bad guy the character is, but we already knew that as we had seen him kill and try to kill people. I almost turned the movie off at this point. I deliberately decided to wait a few days to write my review, as I thought that the complex story layers might make more sense as I went back to them in my head, but instead, I found myself bothered by this disturbing image more than I thought about anything else. If you are an animal lover, you may not want to watch this film.
The six stories vary drastically in their interest. I found the comic episode that takes place in current day to be the most interesting. Some of the others are less successful, particularly one spoken in some type of Pigeon English but is not subtitled. It's almost impossible to follow. However I still enjoyed the film as a whole.