First off, this is pretty much an essential read for anyone who doesn't have a science background. Goldacre gives an easy to understand and funny crash course in basic evaluative tools to assess scientific studies It's also an important reminder of how little time each of us takes to digest what actually requires some time and thought. I highly recommend this to everyone, but especially to anyone currently opposed to vaccines, or convinced of medical "conspiracies" or relying completely on "natural" solutions to problems.
Unfortunately, there is a problem - or rather two - and its a pretty big drawback, especially for those who aren't already on Goldacre's side: Goldacre is extraordinarily condescending. Part of this is a poor style choice that his editor should have fixed; the choice of "you" over "we". But part of it just seems to be him. And I understand that. I understand that you would get tired of repeating yourself; that you'd get tired of seeing the same damn problems that could be solved so easily. The problem is that you won't convert anyone new if you talk down to them. It's a fact. The other side to this problem is that Goldacre assumes a little too much on the part of the reader. Despite his constant professions that he is writing this for a lay audience, he sometimes takes huge jumps from one thing to another; yes many of us can see the causal connections he can't take the time to lay bare, but many more - including, I suspect, the targets of this book - cannot or will not, without a detailed explanation.
But I still think that the book makes an important enough argument, and on the whole that argument is interesting enough, that it is a near-essential read, despite the author's stylistic issues (he is a doctor, after all). So check it out.