3 reasons people dislike this book -
1) It's very maths heavy
2) There are many points where the book discussess uncommon circumstances that your regular player isn't going to come accross very often (he talks about how to beat just about every casino game - you can't expect them all to be as straight forward or easy as blackjack)
3) A lot of people who would consider themselves 'in the know' felt it revealed a bit too much.
On the other hand, JG got himself into the BJHOF very quickly - he's by far the youngest member as far as i'm aware - by writing this book so there's got to be something to it lol. Haven't read it myself, was going to wait for the new edition, but i'm hearing that may not every make it out. I'll give it a bit longer before i buy it off ebay.
RJT.