The other poster pretty much outlined the plot, so I will not repeat it here.
Heather McComb is the only actor I knew in this movie and is the main reason I watched it. Because of a previous role as a 14 year old 4 years earlier, it was a bit of a stretch to believe the now 18-19 year old actress as, again, a 14 year old character, Christiane. However, she did convey some juvenile personality and was very good overall.
The male lead actor, Michael Wyle, was pretty good too, and had many quirks and mannerisms that (I guess) are consistent with his coke head character, Ernest. I wondered throughout the movie how he could afford all his drugs with his crappy job.
The movie is clearly influenced by Taxi Driver, and in fact, I was going to call this review "Taxi Driver Without the Taxi". There is a narration that sounds very similar to Travis Bickle's voice and his comments, and the older male develops a relationship with an underage prostitute, eventually gunning down all the perps. It is not a straight ripoff or homage, but you easily make the connection.
There is also some influence by the book/movie "Christiane F." (about young druggy/prostitutes in Berlin) and the director reveals his one-time near obsession with the book in the commentary. (Great book by the way, but very depressing even though it has an eventual happy-ish ending).
Surprisingly, there is no nudity or sex, although some of the scenes are inside an adult bookstore. The whole subplot of the "special" porn movie that Ernest eventually arranges to see in order to locate the perps is overdone and a bit of a let down (it's 5 minutes long we are told, and costs $1000 to see it once, and $5000 to buy). The bad guy is "sure" this is what Ernest wants to see, although the subject matter is never discussed. If I was paying that kind of money, I would want to have an idea what it was about. I won't spoil it for you, but I found the 30 seconds we are shown to be not erotic. Like I say, this major subplot is very weak.
Not being religious myself, there were a few religious overtones and symbols that were not crystal clear to me.
I rate the movie at 3 stars, a little better than average, but this is also a DVD review, and here is the bad news.
The "behind the scenes featurette" is worthless. It is just rough VCR quality footage of people milling around. No narration, no introduction of the unknown people we are seeing, and worst of all, the sound is very bad.
Although there is a commentary, there is no movie sound at all, so you don't know what the characters are saying, and therefore in many cases, we don't know exactly what the 3 commentators are talking or laughing about. Normally, we could just pop the subtitles on while listening to the commentary but there are no subtitles available on the DVD.
Bottom line - Great movie for fans of Heather or Michael, decent movie on its own, and a pricey DVD for such badly done extras.