When to abandon a book

As anyone following these posts (?) realizes, I am now slogging my way toward the end of "Wolf Hall," and I'm doing so only out of obligation to my excellent book group. I have very much lost interest in and patience with this narrative. Part of me wonders if Hilary Mantel has, also - now that Henry and Anne Boleyn are married, she's been coronated, she's borne him, horrors!, a daughter, we're just clip-clopping along to the inevitable conclusion. It's as if Mantel studied the history and now is filling in the blanks - not that these scenes are badly written, but it's just an endless (seemingly) procession of them, with no real development of character or arc of narrative. Do others disagree? They must - book is selling well, and of course it won the Man Booker (though that's not political, is it?). Or are people's judgments clouded by books considered to be prize-worthy, serious, good for you? I have a reading strategy (obsession?) through which I set mileposts as I start a novel, to determine how it's going, will I finish: 10% of the way through, 100 pages, and half-way through (sometimes the order is different, depending on length). At any of those 3 points I'm willing to stop and move on to another book (will also give any book at least more than one day/night of reading). I think each of those, depending on the type of book, gives you enough info as to whether the book is for you, whether it's worth continuing. Past those points, I'm either very much liking the book or at least curious about the outcome, and I'll quit reading after those points only very rarely (one book I remember thinking the author definitely gave up on near the end, and so did I).