I have seen "Gunga Din" several times. It is not a strict re-telling of the Kipling work but a studio era take on it. It is jingoistic and hokey but it is an entertaining and uplifting film.
Those that bemoan the "un-PC" tone of the film need to look at it in context. The underlying theme of the piece is that these British soldiers come to hold a member of a group of people they had (until that time) regarded as savages, in higher regard than most of their compatriots. The ideas of universal human qualities and nobility are driven home in a very emotional, if a little ham-fisted way. Considering the racial atmosphere in America at the time, this was not exactly a statement without some daring.
To condemn this film or the original story for racism is to miss the point entirely. That was the time and for its time, the messages here are incredibly progressive. Besides, even if the film were racist, only a fool discards a classic piece of art because he or she disagrees with the content of the message. Pretty much all critics and film historians list Griffith's "Birth of a Nation" somewhere in the top 3 films of all time, regardless of the fact that the heroes of the picture are the KKK. The message was wrong but the film transformed the whole of film-making forever. Do we discard that too? Do we burn all copies of Joseph Conrad's novella "Heart of Darkness" because some perceive the narrator to be a bigot? To do so would be robbing generations of a classic example of well crafted storytelling at its best. Such behavior is ignorance in its basest form.
But, you know, that's just what I think.