There was an article about this in the Toronto Star a few weeks ago. The Customs Agents are saying that there are never enough of them to handle the crowds. The problem was supposed to be fixed by now.

http://www.thestar.com/news/article/...gh-immigration

What bothers me about these lineups is that it is chaos when you are backed up in the arrivals hallway prior to going down the escalators (see the picture in the article). People push and shove their way to the front and there is really no crowd control by GTAA staff.

Being based in the US, and having been burned by enough two-hour waits at YYZ customs (not to mention the lineup to get out of the baggage hall once you have your bag) I have started flying into BUF to avoid this. Takes only seconds to pick up a car, and the transit time to TO is about 2 hours. Customs at the Peace Bridge is a breeze. Plus you save $$$ on the airfare even with the cost of a car rental. BUF has really jacked up its airport to accomodate YYZ avoiders, and the flight schedules in and out are pretty amazing.