I attended Gen Con with my girlfriend and a couple friends, and we played in Caedmon Tracey's Sunday morning Between the Lines game. We all agreed that he was not only the best GM any of us had at the convention, but the best GM any of us had ever had at ANY convention.
—His rules knowledge was exemplary.
—He'd extensively prepped the scenario..
—He kept track of time and was conscious of pacing.
However, none of that was what made him great. Tracey's role-playing choices were right on and consistently interesting. The energy and creativity of his portrayals really set him apart: the screeching semi-sanity of his gnolls; the smack-talking Div; the extravagant self-involvement of our patron; the quiet intensity of the seance. It was clear he'd given a lot of deep thought to portraying the people and creatures of his world, and he made that world real.
If you ever get a chance to play in a Caedmon Tracey game, jump at it. He's that good.
I'm a member of the Asheville Pathfinder Lodge, and Caedmon is a regular GM for us there, and he is *always* that good. Three or four of my more memorable PFS moments have been on Caedmon's tables, including a 90 minute philosophical debate during "the Stolen Heir".
If you're ever in AVL, we'd love it if you dropped in - We've got lots of great GMs.