The Tarragon is a nice theatre, and is thankfully air conditioned. This matters to me, because I generally only go to see something at either a Mirvish or Dancap show, or at Fringe, and to this day I recall nothing so much as nearly dying of dehydration at a showing of Cobra: the Musical in the Factory Theatre.
The space at the Tarragon is really good. The chairs are comfortable, and the main space is spacious. The side area is also fairly comfortable.