I'm not sure this is the most sensitive film about autism possible, as there seems to be a Hollywood glossy sheen coating all of it, but Dustin Hoffman certainly immersed himself into the role, and to its credit, the film avoided some form of miraculous transformation in his character. Unfortunately, the kidnapping that somehow doesn't end up with the police involved, the ridiculous scenes in Las Vegas (why they buy suits, how they win, how politely the head of security asks them to leave, etc), and the idea that Tom Cruise's inexperienced character could care for his brother without drama while driving him across the country has none of the authenticity that Hoffman's acting has. The film wanted to broach a developmental disability but also entertain and appeal to the mass market, and for my taste, erred too much on the side of the latter. The transformation in Cruise's character is too abrupt even though the film is long (probably too long), but it redeems itself somewhat with strong final scenes. Worth watching, but not amazing.
Review of Rain Man
