One of those movies that was so influential that a lot of its plot beats now come off as cliche - the broken veteran returning home, the thousand yard stare, etc. There are also some pretty dangerous and backwards attitudes towards women, with characters we're supposed to be rooting for groping, threatening, and outright hitting female characters (in public! With no repercussions!). I also didn't buy Nick's turn at the very end of the film at all.
The film is, however, beautifully acted and shot, and the famous russian roulette scenes are as tense as advertised. Still, there are three or four "Horrors of Viet Nam" films I would recommend over this one, so skip it unless you're a completist.