This film is one of the supreme masterworks of all of American cinema. It is absolutely essential. Yes, it is "difficult." Yes, it is "slow." But those standards are for enterainment. Cassavetes wants to take us out of our ordinary ways of viewing. He wants to deny us the escapism of "entertainment." That's the point. If you have trouble with this film--good! If you find it infuriating--good! If you find it not entertaining--good! It wants to get under your skin. It wants to shake you up.
It is a deep exploration of manhood in America, of the power games that men play with women, and of the other kinds of games women victimize themselves with. Deeper than Citizen Kane, more abrasive than Magnolia or American Beauty, Faces turns the camera on the ordinary, everyday ways men and women treat each other. It wants to get under your skin, and if you allow it to, without giving up or shutting your mind to it, it will profoundly enlighten you.
I also want to highly recommend a stunning book about Cassavetes that makes a nice companion piece to a viewing of the film. Ray Carney's Cassavetes on Cassavetes book (or his web site devoted to Cassavetes) has almost 100 pages about the making of this film. Both throw more light on how Cassavetes got the amazingly intimate and exposed performances he did.
But trust me, this film can change your life. It is one of the greatest works of art in all of film. And the resistance it meets with is proof of it