I don't mind that age doesn't mess with a Jedi's ghostly appearance. But, and I think we've argued this here before but I don't remember the results, wouldn't it be more appropriate for Luke to see his father's Jedi ghost appear as he does the one time Luke actually sees him? As Sebastian Shaw? And, if death doesn't mess with the ghost, then why does Obi Wan still appear as Alec Guinness and not as Ewan McGregor?