My experience with this airport is overall, good. for the new-be traveler however arrival and transferring planes can be confusing. Signs are not wholly helpful and staff is somewhat half-hearted in their efforts. I've seen instances where people changing planes, accidentally end up going through Canadian border crossing when they didn't need to.
Departing Toronto for the USA is absolutely wonderful = everyone clears customers in Toronto and no long lines at their destination. this should be a model for more large international airports.