Speaking of the TYSSE;
It's now part of my daily commute, specifically the use of HWY 407 station. I was actually really impressed by the number of people actually using the station. Throughout the morning rush hour, trains were regularly picking up at least 20-30 people, and dropping off 5-10. Once the 407 transitway finally becomes a real thing, I can see ridership growing to at least 10K PPD, maybe even 15K PPD.
But some criticisms. I don't use 407 to take a GO or YRT bus, I walk to my work directly from there. The access to Jane street is abysmal, and it doesn't even have to be. There are 2 easy pedestrian accesses, but unfortunately, there are "Do not enter" signs everywhere (with, mind you, fines ranging from 500-1000 dollars listed). These should not exist, it's not like you're fare evading by crossing the bus bays, so it shouldn't be illegal for pedestrians at all.
If they want this station to have some ridership improvements, they can at least make it accessible to pedestrians. Developments are coming to Exchange Ave. You should be able to enter the station coming from jane street on the North Side.
Pioneer Village and Finch west are doing very well from a ridership perspective throughout the day (20-50 people getting on at a time), but I really wish the Keele bus would stop inside the bus terminal at Finch West. If the Finch Bus can do it, the Keele bus can as well.
York University is a peak-use only station, but when classes are starting up and ending, the trains get super crowded.
Downsview Park is still dead.
VMC is doing well, about 10-30 passengers getting on/off each train.
Sheppard west station is easily still the busiest station on the extension. I don't think ridership has dropped that significantly (maybe 10K fewer boardings) since the buses were redistributed. It's always busy, but won't crush load a train.
The thing with this extension is that a good portion of the traffic is counter-peak, and within North York/Vaughan, so it doesn't really contribute to crowding on the University line.
Tl;dr Trains are standing room only during peak periods, but not crushed like Sheppard. Pretty empty during off-peak periods, but this is typical of the end of the line segments. Ridership comes out in 2 months so we'll see what's actually happening.