Perhaps the simplest explanation is the best. As a Jays fan, you just have confidence when this guy pitches that he will pitch well and the Jays will have a good chance to win the game. Everything I have heard about this guy is that those around the team are incredibly impressed with his mental approach and composure, and that he 'looks' and thinks like he belongs. The Jays rotation has been so set back this year by injuries (Burnett/Halladay/Chacin) or incompetence (Towers) that you really can't underestimate what his contribution has meant to the team.
Things like that don't necessarily translate to him being a dominant fantasy pitcher, but from a 'real' baseball perspective, he has been extremely effective.
(Just too bad he won't get many shots against the Angels again, he simply owns that team..)