Finished The Shepherd's Crown. This entry says most of my thoughts better than I could. Spoilers, of course, huge honking ones, so don't read until you've read because the book's best approached spoiler-free.
Shall mention however that Pratchett believes in redemption, which is very old-fashioned of him and not what one usually finds in English lit. Calvinism got a surprisingly solid grip on the CofE soul: some people are redeemed or at least qualified to be redeemed, but others are preterite and unregenerately damned, end story. In light literature the preterite are, distressingly often, middle-class vulgarians who don't know their place or have pretensions above their station or whatever the quintessential English social crime is. Has just occurred to me that Pratchett allows even these people to be redeemed, which was nice of him.