If you're going to Paris, spend your time there, not shuttling around in Montreal. If they route you for a quick connection go for it, especially if there is another flight to Paris afterwards in case there is a delay. The Beech is okay for short flights and your seat is both aisle and window. There's a sort of toilet at the back. And if no one is in front of you, the seatback folds down and you can put your feet up. If you wind up in Montreal for a long connection, there are lots of old threads on the subject of visiting in this forum. There is essentially no low cost public transit from YUL and the airport shuttle bus is not a speedster. And Canada Border Services agents are not in the habit of stamping passports of visitors from the US. You don't even need a passport for entry into Canada, just to go home to the US.