I'm in the process of reading it - it's a very interesting book, though I think the bias very ocassionally distorts it. Extremely thought provoking, though, and with a good range of sources, which is always useful.

I certainly don't object to reading things by authors I disagree with - come to that, there's lots in Ratzinger I disagree with, he was just the first person I'd read all day who gave the impression of *thinking* rather than going "Oooh, isn't Mary brilliant". Which is no use from a cultural history perspective, and not that fantastic from the serious theologians, either....