Originally Posted by
carsnoceans
GE will save time on pre-clearing US CBP. You only have to worry about CBSA. Two hours is fair amount of time.
Btw, I have done overnite stays in YYZ. It's not a bad idea if you want to explore the nightlife a bit. Easy shuttle to downtown and a friendly bar crowd.
The real issue is how fast you an get through Canadian immigration/customs and unfortunately GE doesn't help here, just as noted, back through US CBP. Also, if you happen to be doing your flight to YYZ and it's on UA/AC and you're connecting to AA/DL, or vice versa, you'll also have to consider terminal changes.
YYZ now has a rail link between it and the city centre. It runs from T1 (so you'd take the monorail from T3, get off and the Union/Pearson Express is just up the same platform) to the city centre (and would be three blocks from the club and restaurant district) in 25-minutes, runs every 20 minutes. Using the TTC express bus and subway is cheaper but takes about an hour from the airport to most city centre locations.
If your connection at YYZ T1 was from the US to an international flight, the transfer is very easy, with just a quick check of your passport and boarding pass and then back into the international departures pier. Not quite as quick at T3 though. However, in both cases any checked bags would go right onto your international flight and need not be picked up at Canadian customs and rechecked.