The book is relatively short and totally fun to read. It is written as if Mattie Ross wrote it, so you get a lot more depth to her personality. She goes off on rabbit trails, moralising on various subjects and never once considering that she could be wrong. The story line is great, but the way that it is told is great too and the movies can't capture that part.
Included in the audio book read by Donna Tartt (herself a Pulitzer Prize winning novelist) is an essay that she wrote and reads. She has loved the book for years, which helps her read it so well. Also, being from the south, her natural accent is totally appropriate. I have a long commute for work and I've listened to many hundreds of audio books. I generally get them from the library, but I've decided to buy maybe three because they are so good. This is one.
CC Griff