It contains a very negative portrait of McCartney. Why do people get so angry with Macca? He's given pleasure to millions and yet I've met otherwise rational, well adjusted people who spit bile at the mention of his name.
Also, Norman's got a habit of wrapping controversial information in absurdly flowery language. I first read it when I was sixteen and it went completely over my head that one particular passage is about Brian Epstein cottaging in Kings Cross.
Having said that, it's still a great read and well worth the two fifty I paid in 1981.
I can also recommend Revolution In The Head for anyone interested. Ian MacDonald tended to over dramatise (the start of the decline of Western Civilisation was when John Lennon sang "One thing I can tell you is you've got to be free", according to him) but it's a mine of information. Did you know that And Your Bird Can Sing is about Mick Jagger constantly bragging about having Marianne Faithfull as his girlfriend? The song makes a lot more sense when you know that.
And the best bit (I never get tired of writing/taling about the Beatles) is his comparison of Harrison's and Macca's working styles. If you've ever been unfortunate enough to hear Not Guilty you will know what a dog it is. Apparently it took 100 hours of studio time to record a song no one in their right mind would listen to in the first place. Compare this to the blazing guitar solo on Good Morning Good Morning.
http://youtu.be/tqmid9MlFSw(solo begins at 1.16)
Macca just walked into the studio one day while the others were elsewhere and blazed this off in one take (On a Fender Esquire for the technically minded). Maybe that's why people hate him.