I will try not to have any spoilers here. For a complete review of my thoughts on the book, you can find them under my comments on Goodreads.com. The movie and the book are almost completely different stories, with the exception of Abraham Lincoln killing vampires.
Strengths of the Book – Tons of back story on Lincoln as a child, growing up, his struggles to make money, friends, girlfriend, business, law and politics. In the movie, almost all of this historical background with Lincoln is gone. The book also has written journal entries from Lincoln that leave you wondering if he really wrote them and they were incorporated ,or if they are made up. The fight scenes are realistic. Abraham Lincoln is a strong woodsmen, but not superhuman.
Weaknesses of the Book – The first part is never revisited. Henry is not explained, either where he comes from, why he works through human surrogates, or anything. It jumps around, skipping huge chunks of time. In the book, the vampires are about four times stronger than a man, but otherwise pretty easy to kill. The ending leaves the vampires running around, so Abraham Lincoln was really only partially successful.
Strengths of the Movie – Great production values, you get to see scenery from 1818 to 1865 which is very well done. The movie has a great steampunk feel to it, where the book is simply historical vampire fiction. The vampires are stronger and the fight scenes are much better as a result. They can go invisible, etc. I personally also think that the movie strikes a good balance between campy humor and taking it seriously. People who read the book might like less drama over ten hours. People seeing a movie want to see President Lincoln kicking vampire butt, which they accomplish well. The top strength of all – they drop the weak beginning, and actually explain a plausible back story for Henry.
Weaknesses of the Movie - It takes out one of Lincoln’s two friends and replaces him with a slave. It makes the other friend seem unreliable. It adds a super villain vampire named Adam that is not existent in the book. There are a few scenes where Lincoln is wounded, that show wounds from earlier in the movie. The make up folks or editors got some in the wrong order. It is mostly special effects and almost no character development. In truth, you learn very little about Lincoln and the actor portraying him was better at looking like Lincoln than acting like him. He feels like Captain America before the transformation. They also make Abraham Lincoln and his new slave sidekick look supernatural in their abilities. Including, chopping down a tree over a foot thick with one blow. Training is one thing, super powers another.
Movie Comment – The character Henry, played by Dominic Cooper steals the whole show, relegating Lincoln’s wooden acted character to second fiddle. Henry is so well played the other performances suffer from, in my opinion, poor casting or acting.
There, you have my own personal views. I recommend you both read the book and see the movie. After all, it’s Abraham Lincoln killing vampires, you got to see that right?