Progress.
Somewhere (maybe on Steve Munro's blog) I read that the reason that the 506 loops in High Park in the middle of nowhere is that to end the run at Dundas West, there would have to be a third loop which there is not - I forget if the reason is space or cash.
I live in the east end and I know well the situation that has 504 and 505 cars stock-piled at the Danforth light waiting to cross the intersection because the loops there are "full". Today's news that the Flexities are out on 504 in numbers brings us closer to the day when these loops effective capacity will be smaller because the cars are larger. This is going to be interesting if someone has to go to the loo and we can't just switch out a driver and keep things moving along.
Also - the 514 is a bit of a stroke of genius really. It takes a new eastern loop - Cherry - and a disused section of tangent track and loop - Dufferin and diverts however many cars are on 514 away from the congested loops at Broadview and Dundas West. If I were scheduling 504, I'd be moving more cars to that route to take the pressure off the loops.