It is doable (minimum connection time is 1hr). But 'stress free' and 'time for a meal and relax'? No. You get off one plane and get straight on another with a whole bunch of stuff to do in between (walk to Customs, get bag, clear Customs, drop off bag, walk upstairs, go through Security, and go to the gate).

It is not that Customs is busy; it is just a lot of ground to cover in a short time. You can stop for food (e.g.: Tim Horton's once you clear security) but there is no way you are getting a sit down meal in that timeframe.