I hate Fang so I use Snow whenever a Sentinel is needed. I also hate Hope so I don't use him either. My team is usually Lightning, Sazh and Vanille with Snow replacing Lightning or Sazh as needed. Since lately I have been getting to the point where I'm taking on the larger enemies of the pulse-lands and the last of the hunts I have needed a sentinel so I use Lightning, Snow and Vanille.

On personality, I was not so impressed with Snow at first but compared to several other characters his annoying personality became much more bearable in perspective. At least he was just overzealous not whiny (Hope), retarded (Vanille) or bland (Fang).