I play first-person through a lot of dialogue and gameplay, but I switch to third-person when I'm walking beside someone or in a really hardcore story scene.
Would have been nice if they made it so your character's animations were a little nicer to look at in third-person. For example, an animation for turning rather than your character snapping to his new position, or having him look towards the person talking to him rather than just stare blankly into space all the time.
If they fixed those two things I'd probably spend a LOT more time in third-person view.