This is indeed a very short (and scattershot) introduction. It is personal and all over the place but I guess that's the nature of these types of books. It's a long story why I read this, so I won't bother. As someone familiar with the vast majority of the philosophy mentioned, I have to say that it has its good moments and its bad.
For one thing, I think he really doesn't get Mill. Mill is hardly the exponent of utilitarianism that he makes him out to be. Bentham would have never supported the harm principle. He also lumps utilitarianism in with consequentialism; it may well be a form of social consequentialism but that's hardly what people mean when they talk about consequentialism as an ethic.
Also, though labelling Hegel a favourite, he didn't give me any new reasons to bother with someone who I think has to be one of the worst philosophers in history (not in terms of his smarts, obviously, but in terms of his actual philosophy).
The rest of it is fine. And I will still lend it to people looking for an intro, so I can't be too hard on it.