DitV is incredible. If you haven't played it, I highly suggest it. It, like many of the Indie games that have come out recently, is a very inexpensive game. I think that I bought the book for $20.
To address the issue of it being gamist vs. it being narrativist, these are very specific words. The goal with GNS is to help define the creative agendas of players. GNS talks about the idea that certain systems reinforce certain behaviors through their numerical attributions as well as through character advancement. The system itself is always going to have game elements (dice, etc).
GNS theory has evolved into being part of the Big Model, which is also worth looking into if you're into role playing games. In Big Model, GNS are defined as "reasons to explore." Your characters are set up in a world that they explore, exploit and enjoy. Big Model's GNS discusses why the *players* are interested in having their *characters* explore this world.
Gamist:
In the Gamist creative agenda, you explore to prove your abilities as a player. There may be story, there may be accurate depictions of physics, but the main goal is to emphasize tactics, resource management and ass-kicking.
Narrativist:
In Narrativism, the players are having their characters explore certain central themes. Are friends worth dying for? Is dictatorship ever good? Are goblins really worthy of being killed?
Simulationism:
The primary goal of Simulationism focuses on exploration for exploration's sake. I work in an office in front of a computer, that is hardly uproarious adventure. I might like to enjoy exploring a place like Bas-Lag or Elanthia or whatever, just for the sake of being there. Simulationism focuses on realism within a consistent environment.
All games, of course, include aspects of all three. Vincent Baker's goal when writing Dogs in the Vineyard appears to have been to create a game where influencing the evolving narrative is more important than your character's victory or than creating a consistent and realistic environment.
I'd say that of the three creative agendas, DitV has simulationism as its last. You don't really explore much of the game so much as you explore aspects of the self.
The reason that I'd say that it isn't too gamist as well is that winning doesn't really matter. To advance your character, oftentimes it's better to LOSE in a conflict. Winning, in DitV isn't as important as actually getting into conflict.
EDIT:
The Big Model
GNS Theory
