Saw it last night too and was oddly disappointed. Incredible story (in the true sense), well acted, well shot and moving but ultimately unsatisfying. It's worth seeing for sure and hard to watch several scenes but too many themes are left only partly developed IMO. Need to be careful with spoilers etc, but every main act and theme have IMO been developed more powerfully in other films. In this case, it simply moves on to the next one * in what seems to be an attempt to include too many aspects of slavery in one go. As a result, there is a long series of stories all left at a level that ultimately disappoints. At the end of the film, the three of us concluded, glad we came, hard to watch for sure in places , new aspects or slavery that we learned about and made us angry but ultimately something was missing. It was like going to a top restaurant for a taster menu and feeling nice but three/four better developed courses would have been more satisfying.
Having said that, I reckon it's as shoe in for oscars. It's that kind of film.
Brad Pitts cameo is another example of something else being fitted in without adding to the core story IMO.
* the hanging scene being an exception. The length of that shot, his feet, the fact that the other slaves just got on with their business through fear etc developed the horror of the moment. Too often other scenes failed to match this (Patsy and the post perhaps excepted)
I would like to read the book and would expect it to be more powerful and developed.