Flew AC859 ZRH/YYZ in S class. The seat is a standard North America J seat and the seat pitch and degree of decline are "out of ratio". If the person in front of you decide to fully recline the seat, it becomes quite cramp with the person's head about 8 inches from your chin. I was unable to open the tray table to do some work. I couldn't even have lunch before the person sitting in front of me, who incidentally was an AC employee, decided to skip lunch and sleep and refused to pull up the seat back! Fortunately, the flight was not full and I was able to move to another seat. Notwithstanding, for the small premium, it's worth it. The seat is still a lot more comfortable than the economy seat.