The location is super convenient for those who live downtown.
The staff is always kind but still super efficient. Hassles with security have been non-existent in my experience - it's always a very quick process.
And of course, flying Porter is always a pleasure. Who doesn't love a lounge full of free snacks (stock up on the shortbread cookies), drinks (mini water bottles, espresso, coffee, tea) and WiFi?
You can take your pick between the free ferry or pedestrian tunnel to get you to/from the airport. Tip: take the tunnel if you're in a rush.