I used to commute from Downtown to Downsview, and I appreciated the fact that after a day at work, I had a long gradual downhill.
It is easy to find hills if you want them, just go a little farther out, Caledeon and Halton have lots.
Of course if you want a long climb, go to Dundas and climb the escarpment.
Mongol I work at Leslie and Sheppard.