Different "forms" of rapid transit i.e. some forms more rapid than others. People have for years been talking about how LRT is so great in Toronto - but our lines won't have strong signal priority and are often designed with too frequent stops etc. (basically all surface sections go down the middle of a wide road) its more streetcar than American style "LRT".
Toronto is weird, the subways we have broadly move very large numbers of people, and yet we are desperate to import the American model of large trams as the backbone of the transit network on major streets - even though Sheppard's 5 stations or the King car move as many people per day as most entire American LRT networks.
I had promised myself I wouldn't get into another LRT/subway debate ... but here I am.
The issue with most American LRT networks is not that they lack capacity - it's that they run the trains, and nobody uses them, because car culture (and garbage planning). American heavy rail networks suffer from this issue too; San Francisco's BART, Atlanta's MARTA, and Miami (among others) also have low ridership. Toronto is busier than any rail transit network in the US, except the New York City Subway. It's not really about transit mode.
That's not an issue in Toronto; thus, our priority should be finding the most cost-effective way to move the largest amount of people with the shortest travel times. That LRT is not rapid in Toronto, is not an issue with the infrastructure itself, but rather our policies surrounding car use. We could give signal priority to transit vehicles tomorrow, if there was the political will to do so. Frequent stops is a planning issue - I have been critical of the Eglinton LRT in the past, but that's a horse which has already been buried underground and turned into fossil fuels.
The problem with the SSE is cost - $6 billion is an absurd amount of money for a suburban extension with three stations. It's New York expensive. An above ground metro could have worked, but where would it go ...
Since this thread is about the Finch West LRT, let me say that LRT is the best mode for this corridor - it's (relatively) cheap, and it replaces a heavy-demand bus route. Subway is inappropriate for
this corridor in particular, as its demand isn't from through traffic/crosstown traffic, and any stop consolidation with a subway would hurt riders.
The fact that this is a low-key project, I think, is a great example to learn from. You don't have politicians a-les-Fords trying to meddle with it to buy votes, you don't get tunnels (Eglinton West) that are hugely expensive yet pass under single family homes, and you don't have NIMBYs desperately trying to kill the project/make it supremely expensive, in a classic Toronto manner. It also demonstrates that the main driver to cost is poor planning. This is the least expensive, and probably the best-value (or 2nd, after Ontario Line) project built in the last 40 years.
Okay, rant over.