It's too close to the Spadina Line obviously. By Dufferin-Eglinton one's only a hop/skip away from it.
My preferrence would be to use Parkside Dr-Keele St instead of either Roncesvalles or Weston-Galt south of Rogers. Using the rail corridor to save on costs (debatable) neglects the densest areas of the west end that a DRL could and should net (Parkdale, Ronci Village, High Park - that large apartment cluster just NW of Keele Stn, the heart of the Junction - Annette/Dundas/Keele intersection, and the commercial zone Stockyards with lots of townhouse dvlpmts just north of St Clair). Keele's alignment runs stright into the Weston-Galt prior to Rogers Road, so it would be a smooth transition for trains going either direction.