My knowledge of Auster is limited to Sunset Park and this novel, but it seems to me that all his characters speak the same. When reading Invisible, not only I thought all the people in the book had the same tone, but I also felt Adam and Miles of Sunset Park were the same person. Adam resembles Miles (or should I say Miles resembles Adam, because Invisible was written before Sunset Park) in the sense that he's "handsome as a movie star" and very intelligent, bright in sports, a genius in literature, a promising poet, and so on. Does Paul Auster have an obsession about perfect male protagonists? I wouldn't know, because I only read 2 out of his nearly 20 books. But hey, I'm just throwing that theory in the middle. Do with it what you will.
There is also minor talk about the techniques of writing a book, and the title comes from that talk, where Jim mentions when you write in first person, you make yourself "invisible" to yourself. The book plays with all those techniques, first person or third person.
I must admit that the abrupt and mysterious ending infuriated me. Yes, infuriated, maybe because I was expecting a lot from the book, maybe because I trusted Paul Auster very much, but probably because it left me with so many questions. I didn't like it one bit. The journey was enjoyable, but when the book ends, you feel you are handed something irrelevant instead of the thing you were expecting. I felt like I wasted my time. It's not true, but I guess I'm a fan of fulfilling endings.
Yes, it's a good book. You can try it, if you don't mind the slightly somber aura.