I've had for more than one occasion that a Travel Cuts agent refused to route me through Toronto for my trip. For example, my recent trip from YVR-YXU (London ON), the agent only offered to route me through YOW enough though YVR-YYZ is wide open that day on Z class when I made the reservation. Perhaps, the agent wants me to save $7.50 for not stopping in YYZ or maybe they'd rather sell the popular YVR-YYZ flights just to the YYZ bounded travelers who booked later so that they don't have to make a stop enroute.

I also found that Z class is occasionally blocked during peak time flights. I had to travel from YOW-YVR on Aug 17th. I booked in early March and wanted to travel on the morning non-stop AC163. I was told it's sold out on Z and was offered AC213 (2 stops) or AC1187/AC213 through YYC or AC139 (evening). Seats on Z class are limited and schedules are sometimes inconvenient, but afterall it's cheaper!