I've taken luggage on the bus multiple times before, and I'm still alive. I also took luggage on the bus from YUL to downtown a few weeks ago, an act that Anthony Bourdain described as "as much fun as getting a back rub from a rabid bonobo." I usually stay at the Courtyard at Yonge and College, which on public transit is 192 ---> Bloor/Danforth Line ---> two stops south on the Yonge/University/Spadina line to College. Three trips to TO ago, I ended up with major issues with my bags at Bloor/Yonge.
And again, on my next trip in April, I'm flying Porter.