I read this book this week, and can't work out whether I loved it or hated it.
To put things in perspective, I've had reasonable financial success, I was able to retire in my 30s (the first time round), but then got very bored, so went back into forming several companies.
On the love side, it was absolutely intriguing. I have had reasonable financial success, but nothing like that of Mr. Dennis, and every few pages I hit something that made me think hard about how I've run my businesses over the last 10 years.
On the hate side, the Times described him as "an engaging monster", and I can pretty much go along with that. I suspect that I'd enjoy his company (even if I just met him in a pub and didn't know he was richer than Croesus), even while I was outraged with him.
Which takes me to the central "problem" with this book. You most definitely WILL learn from it - I have... but you may well come away deciding that actually you don't want to be rich. As Mr. Dennis himself says, there are rather more worthwhile things to do in life, and rather more enjoyable ones.
Whether I end up deciding the book was hideous, or whether I end up deciding it was stunning, then I'm certainly glad that I bought it and read it.