i do the same commute everyday - if you see blue Yamaha FZ6 with givi hard bags - that's me.
To Front and Yonge from Sheppard and leslie: Don Mills HOV is the best, go on past Eglington. As you approach last entry to DVP you can see if traffic is moving (and usually it is). Get on DVP, you know the rest. If it is stopped - continue on Don Mills S, right to O'connor, O'connor becomes broadview (i think with HOV lane too)
From Dtown back to Sheppard and Leslie - if I leave before or around) 3PM I take Gardiner to DVP to Don Mills N (HOV all the way). if I leave after - front st e to to cherry to bayview extension. Continue on bayview north to mcrae dr, mcrae dr to laird dr, laird dr to eglington. If leslie is stop and go - keep going to don mills (HOV!).
As someone suggested earlier - carefully going trhough bayview also works. my givi bags are narrow (e21) and I have no probs doing it.
So to sum up - to get downtown usually takes me around 20-30 min (HOV really rocks). Back to North York - all depends, anywhere from 20-25 to 40-45 tops