[saltcod]

Shorter, cheaper flights. Toronto to Orlando is 2.5 hrs I think?

[stockresearcher]

All the major Canadian airports also have the US customs and immigration on-site. You go through it as part of the standard airport security process and then the airplane goes to a domestic terminal when it lands, as if the flight had originated within the US. You get off the plane, grab your luggage and leave, no additional lines, security, talking to officials, etc.

The only European airport that does this is Dublin, last I checked.

[jen20]

Shannon also has pre-clearance. The list is small outside of Canada though - Dublin, Shannon, Abu Dhabi, Aruba, Bermuda and Nassau.