I think it is still eminently watchable, despite the absence of the shock which made it such a topic of conversation in its time. The basic themes and the basic backdrop haven't changed. This is one whose lionized reputation has always somewhat mystified me. I didn't think it was great genius when I saw it in 1969, and I still find it just a good movie, not an unforgettable treasure. Whether the movie is great or not, the fact remains that it is archetypal.
Any film buff can view virtually any frame from the film and identify it immediately.
It has soaked into the culture of film, and even into the subconscious of mainstream life, ala Deliverance. Thirty years later, Jay Leno could make a joke about Ratso Rizzo or the movie, and it would be generally understood. After he arrives, he discovers that there are almost no women willing to pay for sex, and if he wants to make a life as a hustler, he'll have to find some better method than propositioning people on the street. Eventually he discovers he'll have to do it with men. But no matter what he tries, the city eats him alive.