I find it a complete disgrace that a city as big and cosmopolitan as Toronto doesn't have a subway line that directly connects us to the Airport. The 192 Express is an acceptable way to get here, but sometimes its a complete pain. I take this bus about 10 times per week (I work at the the Airport) and I cannot help but feel annoyed with this line (And public transit in general) sometimes.
Though this bus is mostly on time, I have been considerably late because of it on more times than I wish to remember. The bus schedule shows that this bus should arrive about every 10 mins, and I think about every 7 mins during rush hrs. I find that 15-20 mins is the amount of time I usually spend waiting for this bus (If I have just missed one). Also, at 8am (when I'm often getting off work after a gruelling 12hr shift) I usually end up having to wait up to 30 mins out in the cold for this bus.
Now, I know that this is the cheapest mode of transportation to and from the airport, but I can't help but be annoyed by all the people with their giant suitcases who get in my way and block the doors, making it almost impossible for me to get out. Specially when I'm in a hurry. (usually when I'm running late because the bus took longer than expected to arrive at stn)
Other than that, this is a pretty decent bus route and the ride from the subway stn to terminal 3 is about 15 mins, and about 25 to terminal 1.