This is a very helpful book. Prof. Wright has presented something that I strongly believe we need to sit down and think about. As an academic who studies evangelicals I am constantly weighing through alarmist self-condemnation and finally someone has had the guts to say that it simply isn't true. Whatever else I say about this book, I think it needs to be read and taken very seriously. Wright calls us to love the truth and be suspicious of statistics, especially when someone is trying to sell you something.
Wright wades through a variety of claims made about Christians, with careful attention to Evangelical Christians. He shows how these claims are often based on erroneous, suspicious or poorly interpreted statistics. He draws on large sample statistics to try and get at what the real situation might be. To his credit this could be very tedious writing, but Wright moves us along at a pace that avoids bogging us down in the details but gives us enough information to see whether or not there is any substance to the claims. I find he is fair. He doesn't paint an overly rosy picture, but he also doesn't paint the doom and gloom we often hear from pulpits.
Wright could have spent a bit more time on the disconnection between his statistically measurable aspects of Christian action and morality. The reality is that the agendas for negative publicity are often filled with strong assumptions about the nature of Christian action and morality. This isn't as much a critique of Wright's choices here as it is of the ideologies behind the internal negative reports on Christian morality. He does get at this with his lovely term "cranky nostalgia", I would simply call it ideologically driven romanticism.
For me the litmus test in terms of bias came when Wright addressed the powder-keg issue of homosexuality. I felt he was very focused, not presenting his own bias but sticking to his task of evaluating Christian attitudes, as measured by the statistics, towards gay individuals. I wonder if he could have been as unbiased towards Mormons and Jehovah's Witnesses as well - he seems to lump them in with other religions despite the fact that they are Christian sects which emerged around the same time as many other "evangelical" sects. Historically it is more helpful to lump them in with the groups they are most related to, regardless of their adherence to classical categories of orthodoxy. The only reason I point this out is that it is a place where Wright's bias does show through.
All in all this is an excellent book. Wright punctuates it with humour (albeit fairly geeky humour) and keeps his analysis succinct and relevant. I highly recommend this book.