It was a quick read, maybe 45,000 words (it was as long as it needed to be and no longer - a resoundingly good thing). The focus of the novel is Eddie Coyle, a small time criminal, his efforts to mitigate a forth coming prison sentence, and the subsequent impact on his acquaintances and associates. The novel is 90% dialog through which the reader discovers the storyline (a method of storytelling I greatly admire). Most of the dialog occurs between no more than two characters at a time. In the novel the persona of each character changes depending on who he is speaking with (just as in real life). This is a wonderful mechanism for "rounding out" a character.
The novel is not without its imperfections (trifling as they are). It is a bit gabby. The speech of some (most) of the characters extends into redundancy and excessive anecdote. One entire chapter is virtually a monologue. Another chapter documenting a conversation between a Federal agent and his boss seemed both irrelevant and unconvincing. In short, the novel would have benefited from a bit of the blue pencil. Not a lot, nothing too radical; where a short story is a tightly written sprint, a novel requires a looser writing style in order to let the reader breathe a bit (even in thrillers).
Creative writing classes should be all about reader psychology. Since even writers have the barest, mostly intuitive understanding of said thing, second best is the study of selected works. I commend The Friends of Eddie Coyle to creative writing classes for both its strengths and its flaws.