Some of it is. It seems to leave quite a bit unsaid about things he mentions in half sentences (e.g. the time he killed someone, him being a Muslim at one point, almost anything to do with the A Team), while there's 40 pages on Leon Spinks. And it's from 1984, so not very up-to-date. Interesting if you're a fan probably, otherwise probably not really worth searching for. He claims he wrote it without a ghost writer, which I can believe, because when I read it it's always im his voice and speech mannerisms.
