The movie adaptation was good, but it didn't do this book justice. Cloud Atlas creeps up on you. Over and over again. When I started the first section, I thought I wouldn't be able to finish the book. The language and period and setting were all somewhat off-putting for me, and I wondered why anyone had ever recommended it to me. But then I got the hang of it, and I started to care about the characters and wonder about what would happen...until the rug was pulled out from under me. And the cycle repeated, with increasing velocity, straight through to the almost unintelligible center. A center with such a challenging narrative voice that I almost certainly could not have endured it as the first or only part of the book. That may sound like faint praise, but to me it's an amazing feat to make something that would otherwise be difficult feel worth the effort. So much so that by the time you've reached the end it didn't really feel like an effort at all.
In this book, Mitchell gives you so much to chew on, so many ways to enjoy the reading experience. Interesting structure, linguistic dexterity, clever self-reference, subtle symmetry. It's also loaded with drama, action, mystery, romance, humor. Unlike a lot of "important" literary works, Cloud Atlas provide ample intellectual stimulation while also showing you a good time. It flirts with the genre-lover in you, then leaves you hanging in prolonged suspense, feeling the agony of an abandoned story right when all hope is lost, before finally turning the corner, showering you with hope and giving you multiple, satisfying resolutions.