I actually found that I enjoyed Matheson's writing though. It is easy to feel for Neville; his anguish is transferred through the pages very realistically.
I found the novel to be very much less stressful than the movie except for the sexual theme introduced. It was weird, and pretty unnecessary, if you ask me. Maybe Matheson wrote it in to add to Neville's humanity, but I think that his pain is already human enough. The fact that it was introduced on one of the first pages was also a bit much. It was as if Matheson wanted to make sure that the reader knew that Neville was still very much a man. It seemed obvious to me, but I don't know, maybe not to others.
The most obvious difference between the vampires in I Am Legend and the others we have read about is their complete lack of intelligence. Matheson's vampires are mindless, only focused on hunting down Neville. Whereas the other vampires we've read about are refined and interesting. They are able to see beyond their thirst and have interests besides drinking blood. This gives them humanity where Matheson's vampires have none. From this, I believe that Matheson is making a comment on his society's humanity. This book was written soon after World War II and could be a comment on the war's ending. I Am Legend is also an apocolyptic novel, therefore it could be a comment on the atomic bombs and the world ceasing to exist because of them.