If there is only one thing you need to know about Duo, it's that you need to get there right when they open otherwise you will be SOL because the pastries go FAST.
I came here at 4pm last Friday and there was probably 10 things on the counter. It was depressing.
Duo is a small café with limited seating, delicious caffeinated drinks, and the best croissants and pastries you can get in the city. Expect to see a line if you come on a weekend morning.
The croissants are just like the ones you would find in Quebec and, I've been told, Paris, although I've never been there myself. They are buttery layered pieces of art and best eaten fresh (duh). You can get them with various sweet or savoury fillings from roast beef and mushroom, spicy salami and cheese (my favourite!!), pistachio, almond etc. Or if you're a purest you can get the plain one. Enjoyed with a latte or cappuccino, it's the perfect start to the morning.
The pastries are also worth a mention. They are not too sweet and full of flavour. You can tell that sugar isn't added as a filler but as a flavour enhancement. I've had the coconut nectar and the apple tart. Both excellent!
Service is always friendly and fast. They toast the croissants for you if you eat them in-house! If you buy 6 then you save on the tax. Parking is easily found in the lot right outside.