I actually liked the first half of this book quite a bit, but Alister McGrath lost me in the second half. The biggest problem is that McGrath closely identifies atheism with communism and particularly with Stalinism. For many of us, that makes most of the critique irrelevant - communism of the Marxist-Leninist varieties is formally atheistic, but to some of us it is basically just another religion. It's exactly the sort of apocalyptic, totalizing system that we see ourselves as fighting against.
It's interesting that McGrath went from one such system to another.
Still, The Twilight of Atheism provides some good historical discussion in the first half, and it does provide examples of some of the most popular misconceptions about atheism.