I didn't realize before this was posted that Lee Ermey was only intended to be a technical adviser.  Having seen him in multiple movies, I must say that he was the perfect choice for the DI.  His personal experiences and delivery lent a stellar sense of realism.  I agree with you that it should be preserved, but I feel it should be for different reasons.  Full Metal Jacket shows the mental and physical abuse-whether on purpose or unintentional-many recruits are subjected to.  Being from a military family with member(s) who served in Vietnam, I have a bit of a personal connection.  Thank you for choosing this movie.  It is, without a doubt, one of my favorite movies.