Can't complain. In comparison to other major airports, Pearson is actually quite clean. I, myself, haven't experienced any delays or cancellations so far (thank God for that, hope it stays that way) but when those situations do occur, it's not really the airport's fault, more like mother nature's fault. I've always had good customer service with Pearson from the check-in counters to customs. Everyone was very willing to assist you if you needed help. Of course duty free is a plus for me seeing that I was left in a state of shock realizing other airports like Buffalo, Chicago or LAX didn't have duty free, or maybe I just struggled to find it. Anyways, 4 stars! Only thing is, I wish the parking didn't cost so much.