Personally I prefer taking a bus to MK over driving 9 times out of 10. Bypassing the need to deal with the TTC/Ferry Boat/Monorail and having the bus take your straight to the bus plaza in front of the MK is a very nice benefit.
Unless you just really want to the control of your own car / control of your own environment (both very valid considerations at the moment), and want to ride the Ferry Boat or Monorail, I lean towards the bus.