Nick Mason has just about everything it takes: he can write, with a very dry (and wry) sense of humour; he's charmingly British; and he's been there all along. There are only two (minor or major I let you decide) drawbacks about this book: first, Mason has always been quite in the background as far as the artistic/creative process in Pink Floyd is concerned. He's never really been one of the songwriters, so he's not quite in the position of giving you the 'vision' behind the songs or the albums, the way Gilmour or Waters might (but won't); and secondly, he is obviously very wary about stepping on his bandmates' toes. So you probably won't learn anything really new about the songs; but you probably won't learn anything new about the band, either. Mr. Mason is very, very reserved if not reticent when talking about his bandmates. Just as an example, the only thing we learn about Rick Wright, in the first 200 or so pages, is that he played organ... So what do you get instead? You get plenty of meticulous descriptions of venues and gigs, with anecdotes mainly regarding roadies, or managers, or other associates. Nothing too personal, of course. But always sublimely written, nonetheless.
All considered, if you want a not-really-informative but witty, and reasonably entertaining account, this sort of "Pink Floyd as told by P. G. Wodehouse" might be your book. But if you're looking for some exhaustive, thoroughly researched biography of Pink Floyd, I rather suggest "Pigs Might Fly - The Inside Story of Pink Floyd" by Mark Blake.