I was curious about the stories though, and decided to look up the "spoilers" to see how it all ended. I found a website, that gave a summary of each story, as a complete story, instead of an endless series of fragments:
The Movie Spoiler: Cloud Atlas
NOTE: This spoiler was submitted by L. who says, "The film’s stories are all intertwined and scenes intercut with one another. Unfortunately, I can’t recall every editing choice so for simplicities sake, I broke down each story into chronological order – which robs part of the film’s beauty and doesn’t do it as much justice.The reviewer claims this presentation of the stories, in chronological order, robs part of the films beauty, etc. But I actually enjoyed this summary more than trying to watch the movie! Reading this was quicker, and less irritating. The ending isn't bad, but if I had to sit through that movie for three hours for that ending, I would not have felt it was worth it. If they had shown the stories in chronological order, and edited it down some to pick up the pace, it might have made a better movie.
The stories are simple but the structure is divine. Your viewing experience will be MUCH different from this spoiler." [...]
The historical inaccuracies were also annoying; mixing up geography and people in places they never were, etc. Sloppy. Why mislead people about facts, when with a little effort, it could be accurate? I hate to be saying so many bad things about it, but I am saying them, because it was ALMOST an enjoyable movie. The story summary made it seem like it could have been pretty good. A bad movie you can forget. But an almost good one, is a bit tragic.
The film got high marks on the IMDB, so perhaps my opinion is a minority view. But if you also found the film tedious, but somewhat interesting, you might also enjoy reading the full spoiler summary at the above link.