They did the WORST job with Luisa Ray's story. Like, omg. How could they do it so badly?!
But the Cavendish one was one of the few times the movie struck the right tone, the same tone as the book. Part of what's so brilliant about Cloud Atlas is the author's ability to swing completely and authentically from one style of writing to another. I read someone describing the Luisa Ray section as something like an airport thriller/mystery book. And that is exactly how it came across and why it delighted me so much. It was almost cliche on purpose. And then you go from that to Cavendish's story which is written in such a perfectly British way. I mean, so perfect. Then the Sonmi parts were just exactly dystopian too. Really, the book just amps things up and up and gets better as it goes.
I wasn't fond of the 6th and central story though. That one bored me the most and it's mostly cause I found the style to be almost insufferable.