Located across downtown Toronto. This airport has a free shuttle bus that picks people up on front street. During summer can choose to option to take the ferry across. It's a bit longer then the tunnel but can be a fun experience for the kids.
Small check in area as not a lot of traffic but there are hourly flights to Montreal.
I love there complementary snack section. They have Starbucks coffee, tea, cookies, pretzels, water, coke, ice tea all free of charge.