What would Will Eisner have thought?

Eisner and Miller were friends, at least, on a professional level. However, they had very different approaches to their stories, from a writing standpoint. Miller adapted many of Eisner's visual stylings, but not necessarily his focus on people. I doubt Eisner would have liked this take, but I suspect he would credit Miller for doing it his own way. I suspect he would have been less kind if it were someone other than Miller directing and the result was the same.

"Outside of a dog, a book is man's best friend. Inside of a dog, it's too dark to read."-Groucho

Well, if Miller and Eisner hadn't already been familiar with each other, and Eisner had lived to see Miller's film of The Spirit without their friendship, I think he'd have said: "Hey, that guy in the mask looks just like The Spirit!"

In other words, I don't think there's much in the film that resembles the comic strip. Miller's storytelling style is comparatively deep for comics, but painfully shallow and pretentious for film.