I don't know if anybody noticed this, but to keep elevateds from costing too much, the columns take lanes away from traffic. Almost certainly the supports for a station structure will eliminate turn lanes.
Just like LRT, except costs twice as much if not more.
The primary reason Vancouver went with elevated skytrain over subways is mostly because of the complicated geology underlying the city. The Canada line is elevated through Richmond because that city is built on what is essentially quicksand and the tunnel will float right out of the ground if there's even a moderate earthquake while an elevated structure is more stable in such circumstances.
REad in the globe that it would cost around 100 mil so around the ball park of on street LRT. I think the added cost will probably be worth it as we get rapid transit speeds and we can maintain using the LRT vehicles if we want thus less penalties. How I see is is that they can build the Eglinton LRT tunnel and convert the at grade sections to elevated using the cancelled Finch LRT money (which probably had no chance of surviving under Ford anyway). Then we can go ahead with the SRT LRT conversion anyway and Sheppard can have the 4 car subway line elevated the rest of the way to STC, if not the money can probably bring them to Kennedy right now anyway if we used elevated.
Also they should market the new lines as subway anyway since they all basically have underground segments. Probably would deflect some criticism.