YYZ (the stuff provided by the GTAA) is excellent. If you run a channel sniffer, they have access points provisioned on literally every 2.4GHz and 5GHz channel that is licensed for use in Canada. Download speeds seem pretty good. I'm really not sure what the complaint is as YYZ's WiFi appears to be basically a model for robust public WiFi access.

The MLLs, on the other hand, at least at YVR and YYZ, would be better off turning over the whole WiFi thing to the airport authorities to provide.

To the OP, you sure there's nothing wrong with your hardware? Because what you're saying about the Pearson Free WiFi runs entirely contrary to my experience.