If you grew up in this time and place, or a reasonable facsimile, you will understand and appreciate this little gem of a movie. If you didn't, you won't.
Those of us that did will instantly recognize the time, place and character types portrayed here.
Its strong points are its accurate capture of the milieu and the characters. In that case, the lack of character development is a positive part of the characters themselves, not a shortcoming. We know at the outset that most of them are not going to be able to break out from who or what they are, and the ones that survive Viet Nam will end up back in the neighborhood or a transplanted version of it. Even when one character recognizes his limited prospects, we're not really sure that he is going to be able to do anything about it. That's what gives the story line, such as it is, its bite.
On the other hand, the meandering plot and the technical shortcomings keep this film from achieving all that it could have. If the plot had come up to the standards of the characters and the period accuracy, and if just a little more attention had been paid to technique, this would have been a classic.
As it is, it's not quite there. But despite its shortcomings, it deserves a place among others of its type.