The Director's Cut is about five minutes longer than the Theatrical Version and features five new scenes, for example a new scene with an argument between Liz and David, which motivates their break up later and another scenes deepens the figure of Delia, but generally these new scenes aren't that interesting. One could say, they only speak out what has so far left unsaid. Since both versions are on the same DVD/BluRay there's no need to decide which version to buy.