The film is interesting in its segmentation into various 'topics' (e.g. rats) and the various levels of how these individuals deal with the living situation is quite moving. There are enough diverse opinions given that one gets a good understanding of the 'glories' of such a life yet it also reveals that it is not always as it appears.
My only critique would be that this is but a small segment of the population and there are many who are less well spoken and who are far worse off in terms of problems (mental health, substance abuse or other) whose lives are considerably worse, whose stories are not seen.
But as a whole this is by far the least judgmental and sensationalized film on the subject I have yet seen.
Definitley get the DVD. It contains updates of the people in the film and an excellent interview with the director himself. The way the film came together is almost as fascinating as the stories of the individuals in the film. More importantly, I believe, you'll see where his heart was in making the film and it really adds insight to the film revealing that it is much more than 'just' a documentary.
There are also clips of footage that didn't make it into the original film. The music is by DJ Shadow whose music is worth checking out also.