One thing in the novel that I always miss from the film is when Luke falls away from Vader at the end of the duel, Vader held him in that space, and then let him drop...it showed Vader 'letting' Luke go.
But I'm not sure if that was filmed or not.
Also, in that scene where Vader tempts Luke, any chance you can fix his helmet from blowing / wobbling around in the wind? That always annoied the hell out of me!