I thought The Book of Eli was really well made. The directors did a great job of conveying the dried up and desolate environment. In fact, between Book of Eli and The Road, I'd say BoE actually did a better job presenting that bleak vision. Of course, BoE also probably had a much bigger budget then The Road.
The action scenes are also filmed wonderfully. Denzel Washington and his rather prominent machete turn into a spinning dervish, slicing apart foes in a seemingly effortless ballet of blood and gore.
However, it did have two problems in my mind.
Mila Kunis acted like a regular kid from today's society, instead of a kid born in a post-apocalyptic wasteland, and with all the stunted education and trauma that would go along with that. Basically, she acted too much like regular Mila Kunis.
The second problem is Eli being blind. I know this is the big twist, but I really disliked it, because the rest of the movie makes no sense. The things he did were not things that a blind man should be able to do, unless that man is Daredevil. And I'm sorry, but I thought I was watching a gritty, somewhat realistic take on the apocalypse, and not a superhero film. Blind people's skills will sharpen to compensate for their lack of vision, but not enough to pull off the things Eli did here. And honestly, the movie itself didn't need the twist at the end. It's wholly possible that Eli was a regular guy who just happened to be able to read braille. Braille isn't something only blind people can read.