For Canada Line in particular, I quite like walking under the SkyTrain tracks in Richmond. It uses newer technology so you almost couldn't hear the train above you, it's extremely quiet. Also, it's a great weather shelter. In the summer it blocks the sun, in the winter it blocks the rain. Lastly, there has been art installations under the tracks and on the pillars making it very very pleasant to walk through. Some people say "The elevated tracks are not that bad on Canada Line", I would say, it's a fantastic addition to No. 3 Road, making it much much more walkable.
Thinking about this more, I think a Skytrain-style elevated guideway would actually 'enhance' the walkability of suburban Eglinton -- a modern guideway provides optional shelter from the sun & rain if you want to walk underneath it -- and I agree there's been a huge increase of pedestrians underneath Skytrain lines, which show that a modern guideway can be integrated well into a suburban landscape, and be an attraction into itself for pedestrians. The Shanghai-style would be too much clutter, but the Skytrain-style would be perfectly fine in low-density suburbania, especially if a nice pedestrian walkway is well-integrated underneath. And the 30-year-old Skytrain guideways have survived pretty well, probably not going to go into true ugliness anytime soon if maintained well. And nowadays, they can put a nice continuous strip of nice LED lighting to brightly illuminate the path at night, too.
One big question I do have, is how wide the guideway needs to be for heavy rail, versus SkyTrain technology. Another big question is I know that way more salt is used in Toronto than Vancouver, so that can age a concrete structure faster. Another big question is the extra noise of heavy rail technology over SkyTrain style technology. They could
ban salt on the raised structures, however, and perhaps limit speed past residental areas in the late evenings (with adjusted timetables), so there are solutions to keep it desirable and pretty 50 years from now.
It would take time to convince Toronto, though. A good marketing campaign is needed, to show the pluses of the slim Skytrain guideway versus ugly-crumbling Gardiner. Also, good 'realistic' concept art is needed, and promises of never using salt on the raised structures, plus pictures of Skytrain at its best.
Chopping the Eglinton spur would be quite fine with me, replacing it with an ECLRT extension to Square One, but if we're essentially installing a new grade-separated line down Eglinton, I see a Skytrain-style slim elevated line actually benefitting suburban Eglinton. Then we don't need this raised-SmartTrack discussion at all (though I *could* see ECLRT being someday upgraded to an elevated dedicated-ROW -- maybe not within my lifetime -- once traffic warrants).