I've read more than half of the book's 509 pages in under three days, which might sound like Rookie-numbers to some, but for me it's quite the achievement.
It really depends on the book I'd say; If the book piques your interest, it reads much smoother, at least that's what I noticed with the chapters so-far, some read E-Z-P-Z, and some are quite a hassle to "chew" through...