Stephen changed a lot from the book, but I didn't end up minding it as much as I thought I would. (and they went into detail about the Aunt Helen story instead of just briefly mentioning it, and I cried [for Charlie not Aunt Helen])
I liked this film, but I wouldn't recommend it to just anyone. In order to properly enjoy it you have to be open-minded. That being said, I thought Caleb Landry Jones and the directing style were both amazing.
I'm a big Jack Kerouac fan so even though there was a few things I would've changed, this movie was not a disappointment- the soundtrack, the scenery and the performances were all great. Bravo to the cast and crew because this movie was amazing.