The Woodbine connection is strange indeed, and I don't even know what gave them such idea. The eastern leg of DRL should go to Pape / Danforth, that route would be both more effective (in relieving Yonge) and cheaper (since it is shorter).
I think Woodbine is intriguing and potentially brilliant . . . and it may ultimately be even more cost effective than you're suggesting.
Woodbine - Kingston Rd - Queen means a gentler curve, which will translate into a faster journey. It'll also be doable as a cut and cover trench in its entirety, which AFAIK tends to be the most cost-effective method of subway construction. Additionally, Woodbine and Kingston will handily support rezoning for intensification, which means that development can potentially be piggybacked onto station construction, maximizing the ROI. Pape is a poor choice for all three of these: in particular, since it would need to be bored (expensively) under predominantly low-density established residential side streets, it is difficult to imagine how they would be conducive to the densification required for leveraging local ridership. The proposed Woodbine route will succeed on all three counts.
An interesting question then is: what will become of the streetcar to the Beaches? Hopefully it will turn southbound at Coxwell and then go along the median in the middle of Lakeshore over to Queens Quay and then into Union Station.
But that's a topic for another thread.
A big problem here is that the Yonge Subway, Bloor-Yonge Station, Union Station, and the surface streetcar network all need to be 'relieved'. Obviously its a consequence of underinvestment in downtown transit relative to travel demand, and now we're forced to catch up quickly. Knowing that realistically we'll be lucky to get one tunnel dug in the next 30 years, they're trying to solve several problems at once, which is going to become a compromised design no matter what is chosen.
Yep, and I also think they're trying to avoid having to deal with all the hidden extra costs inherent to going underneath the PATH and through the CBD, which is why King and Wellington were out of the running.
One more thing to add:
I realize that the DRL is something dear to many people who've invested countless hours designing their own routes and fantasy maps based on what they thought was best. Some of them are clearly dissatisfied with this route map in preference of their own.
Most of the maps I have seen over the years are subway-centric only, and don't take into account the existing GO and streetcar infrastructure that's already there, waiting to be leveraged. That's the perspective Metrolinx is coming at this from. It's already looking at the day when electrified GO trains are running every 5-15 minutes. It's already eyeing a midtown commuter line that runs from Kipling to Scarborough. And based on the realities of the last 30 years, it's probably already weighing what's financially and politically feasible.
This line reminds me a lot of London's Victoria line: built for speed, relief, and maximum connectivity with other lines. Like I said, this proposal is intriguing and potentially brilliant.