Mmmm. I'd have been happy to accept that Vader has a shorter "battle" helmet and that the "kilt" was a one-off for similar reasons — we never really see him going into battle elsewhere, the closest is the opening of ANH. For his sabre battles in the three movies he doesn't really have the opportunity to go back to his quarters and change. :-p

That said, it's ridiculously awesome that Ady's managed to do that. I don't know how many times someone has suggested something, and we've agreed "that'd be cool but it's practically impossible to do", and then Ady comes along, says "it's already been fixed", and leaves us in his wake.