Not sure why the UPX service, with DMUs every 15-minutes isn't a metro system. It's most certainly custromized - I doubt there are luggage racks like that on the other trains.
We get caught up in headway when its become X time to say what it is or isn't when in fact, we have far better headway than most places around the world for x system.
You can find luggage racks on various system to the point Gold Coast has added places for surf boards to be store on top of other things.
As systems move to larger cars, yards and maintenance buildings will become an issue and TTC is no exceptions. TTC is already looking for a new yard with it being out in the west end. Then look at what taking [lace at Wilson yard.
If the SRT conversion had gone LRT as plan, there was to be a new yard east of the current yard.
Based on past track record of TTC, line 2 always gets the hand down from line 1 and that will have major issues for Greenwood. You never know if TTC will stick to the TR for Line 2 since there will be more than they need for the line in the first place.
There is nothing wrong having a yard with no loop if the cars are to run in one direction in the first place and Crosstown is no exception.
As noted, even though cars are to be off the shelf model, each systems like something different than the other systems.
The reason UPX cars are the same as SMART cars is because Metrolinx had no time to look around and they were FRA approved in the first place. Look what happen locking onto someone else order who still has issues with the order and not in service yet.
Even railways these days have issues with their yards since car where only 30-40' long when yards were built and train length were only about 60 cars. Today, we have cars up to 89' long and train length from 100-200 car long that can requires 2-4 tracks to makeup or break down to the point new yards are being built up to 6 miles long to handle these longer trains.