Take Frodo Baggins, Thomas Covenant, Malta Vestrit, Jon Snow, Miles Vorkosigan, Sherlock Holmes or any of the countless prominent characters from fiction of any genre -- they are all quite exceptional, but also significantly flawed in one or many ways. I didn't see any prominent flaws in Kvothe, which made him really boring and uninteresting; now, as someone else mentioned, he is an unreliable narrator of his own life story, and it is quite possible that in later books it will turn out that a lot if it was a lie and his flaws will be revealed, but by then I have long lost my interest and I don't think I'll ever get that far. I do enjoy a good twist in the story, but the story up to that point needs to be interesting on its own; Usual Suspects wouldn't work at all if Verbal Kint was a flawless character.