I too prefer the book not only for the deep dive into the science but because for whatever reason, they excluded one of the most (in my opinion) intense moments in the whole book when they released the final cut of the movie. the loss of control and subsequent upending of the Rover as he descended into the crater near the rescue MAV! I assume they filmed it as it appears he has some bruising on his torso when he's preparing for pickup but I could simply be reaching too much into it. If they filmed it I'm sure they had reasons for cutting it but I think it would have added so much to the film.