I actually saw the movie first, it intrigued me to read the books. So within one week, I read all 4 books and the extra one on Links. To be honest, I think they cast the right actors to portray the characters. I know the script wasn't dead on, only 50% of what happened in the first book.
But to be fair a) the first movie would have had to been done in two parts to do everything that happened in the book. And it being the first one, they aren't going to waste that money on it. So I think it was fair and hopefully intrigue more people to go run and read the books.
Another thing, I actually liked the ending of the movie. Ethan screaming out for Lena was very touching. But hopefully they will, if they make a second movie, stick to the book now that they know (hopefully) it will do well. The second book is by far my favorite still. I loved Ethan's and Lena's struggle and the unknown relationship with Liv during their struggle. *spoiler* However, I was glad the authors didn't cross the line and have them kiss because it would had been another love triangle and I didn't want that. I liked Liv and Ethan as friends. Plus her and John are amazing together!