I’m a sucker for Penguin books, especially gigantic ones. Anybody else read it or heard about it and want to share some thoughts?
So far: scope is immense, narrative not too jumpy, delightfully dry humo(u)r, and steady but gracious analyses. I’ve only got 200 pages left!
Never heard much about it, although the title seemed familiar when I saw it.
Report! 
Well, it took a while–to put it euphemistically, I’m a careful reader–but what a delight! There is no point trying to summarize besides saying that he is thorough in his task.
I learned about lots of groups of Christians that I hadn’t been introduced to before. If I had been introduced to them, this account generally was more charitable as to their raison d’etre. Where/when/why certain groups emerged and dwindled is to see how humanity has struggled with god over time. In a conversation with Sobornost (after I came across the term in the book) I marveled at the breadth of Christian expression. As Universalists, sobornost gains a new dimension, encompassing the belief/love that all will have for god as his love for us unfolds.
If anyone is looking for a great way of peeking in all the dusty corners of Christian experience, this is perfect. You’ll certainly bookmark things to study further, and MacCulloch’s broad strokes do as much as his finer details. The story traces trends and themes, developing them through accounts of groups and individuals grasping at god’s nature and how to manifest it in the world.