Simply put, this is a very good fantasy novel. The big thing I am struck with is that this is not a novel commissioned just to serve as iller for the game setting. It never feels clunky. Sure, there are refernces to spider climb, magic missle, wall of ice etc, but its never 'Varian casts a 4th lvl spell wall of ice". Its done as well as you can do while incorporating the game mechanics of the world in which its based.
I actually do appreciate that Dave makes the effort. It would feel wrong to write a pathfinder based novel and have Varian not be bound by the mechanics of that world.
I agree that Dave Gross does a great job at incorporating game mechanics into the stories without making it obvious. I am looking forward to rereading Queen of Thorns once I finish rereading Master of Devils.
If I may recommend another Tales novel, you should check out Blood of the City by Robin D. Laws. He also does a great job (maybe even a better job?) at putting in the game mechanics (spell components, character leveling, etc) without smacking you in the head with the Core Rulebook.