Yes, I read it a few years back and didn't get on with it either.

It's fading into the depths of my memory now, but I think I recall that one thing I particularly disliked was that it over-sold the psychological transformation of [hastily googles up name] Sandoz; I remember them making a big deal about the stresses which had turned a previously saintly man into somebody who could commit the brutal murder of an innocent, and when it finally came to it, it turned out that actually what he'd done was to attempt to escape from prison and accidentally killed someone he'd liked instead through mistaken identity. Perhaps the point was that Catholic theology would not have considered that any kind of excuse (I have no idea), but fine points of morality aside, it seemed clear to me that you need far less distortion of his previous psychology to get that far, so it struck me that they'd built up a lot of expectation and then not fulfilled it – which was especially annoying since I'd only stuck with it through the squicky bits in the hope of finding a satisfying answer to that particular thing.