I will start by saying I have never read the book so I'm basing my review solely on the film.
I actually found the film very hard to watch and cried most of the way through. It is a very beautiful film but I think what is unfortunately overlooked my many is that the strongest relationship in the film is that between John and his father and it is this relationship that made the film very emotional for me. In particular scene following his fathers stroke where John was reading the letter was beautifully done and very well acted and was the scene I found most upsetting.
I think the film explores a number of important aspects in particular having an autistic parent which I could only imagine would be exceptionally difficult for any child, particularly when said parent is their only carer. As seen with the characters of both Aaron and Johns father relationships are often quite difficult for those with some types of autism, routine is important and going against a routine can cause a lot of angst and distress. Its unfortunate that a number of people continue to see autism as an excuse for peoples bad behaviour and I think this film brings and important note to an often misunderstood illness. It also points out the issue of autism in parents which is another issue often overlooked.
The relationship between John and Savannah is only secondary to that of John and his father and I think its well acted by Channing Tatum and Amanda Seyfried. To me both actors seemed to really feel and understand their characters and the hurt between them and I did like how the ending between them was really left open to interpretation.
In all a very well done film which explores some important social issues but no review will ever truly do this film justice. I for one could not watch it again because it made me so upset but this just goes to show how emotive the film is. Its a film that needs to be watched, even if it is only once.