AtD gets sidetracked with long stretches of s&m-laden filth. GR reads like a fever dream but it's interesting both thematically and in prose (it's also dirty, but doesn't linger as much).
I don't remember AtD as being particularly filthy, but it has been a long time. It remains one of my all-time favorites. If nothing else, I'm indebted to the book for encouraging me to seek out literary westerns such as Warlock by Oakley Hall and Butcher's Crossing by John Williams.