Summary: I love this airport.
Pros: clean; organized check in area and nice waiting area; complementary wifi; many power stations and tables where you can work
Cons: security check is a mess; I wish it would be bigger;
Details: It's a major Toronto airport. There is Porter, but it's in the city and very convenient for people that live downtown, but not to the folks from GTA (Great Toronto Area).
Pearson is great for domestic and international flights. Both terminals have plenty comfortable places to wait for your flight. Duty Free is tiny and the airport does not have many food places. However, you will not die from starvation and you can always find a small gift for your friends :).