Murphy dismissed the thing I among others have said, about art film being mostly conceptual and that you can pretty much skip the movie. He actually sat through the full eight hours of Empire as well as Sleep which was over five and a half hours. Gushed over how great both of them were, but I'm still not buying it.
...It was shot in black and white. I believe it was shot in negative film and negative is very difficult film to deal with and he obviously brought it to a lab that didn't know how to handle the film very well and consequently there are a lot of blotches and marks on these very strange patterns that actually appear on the film stock. So between the depth of the image and the material of the film, there's this sort of tension but it really starts to appear like stars in the galaxy. It's a little bit like the Vija Celmins "Starry Night" painting series. That's the experience of the film for me. Each section is different and I describe it in some detail just because it was important to get at what happens, but it's not that nothing happens. There's actually quite a bit happens in the course of that film as different lights get turned off and things change that you have these marks on the film. You seem to be on this journey. So I think it's very interesting that he didn't film it during the course of the day which is, you know, I think most people would have thought he would do but that he figured out to do it that way. Warhol was into high concepts. Like the idea of five hours plus of a person sleeping and everybody thinks then, "Oh, I don't have to see the film." And the same thing with eight hours of the Empire State Building.You can read the full transcript or listen to it here.
Also you can look at Murphy's website here.