Im not sure about Downsview, but Aurora has a lot of speed limit changes. I just took my G there a month and a half ago, and you should definitely be familiar with the area. It is very easy to speed in aurora as the speed changes from 70km to 50 km at some intersections and vice versa. Im not sure how the m2 exit works but you should do fine at either location, as long as you observant.
It's pretty much the same with Downsview (I got my M there). The roads within the vicinity of the MTO has posted limit of 30km/h, with speed bumps. Big stop signs sprinkled around also. Try not to blow any of the above mentioned, even in first gear. The whole test is on how observant you are with your surroundings (traffic, road signs, pedestrians, etc.)
I know it's a test and majority of people do get a bit nervous because someone's watching you. Just ride normal, like you would & should everyday, or just behave for 45min and you'll be fine. I do believe they take marks off if you go too slow to the speed limit, like 55 in a 70 zone
The 2 marks I got was following too close (not when moving)... you need to leave 1 bike length between your bike and the vehicle in front of you when you are stopped at a traffic light.
I do encourage you to ask the MTO examiner any questions you may have before your test, and set expectations so that neither of you will be surprised. One question I asked was: what's your expectation in terms of merging onto the highway? as you know the posted limit is 100, but 401 traffic usually moves faster than that. Are you okay with me matching speed in a safe manner to complete the merge, then drop back down to 100? or I cannot go over 100 period? He was a rider himself, and his response was "I'm okay with you matching speed, just don't do anything crazy like 120 and you do need to drop back down to 100"
Oh yeah, they also look at how comfortable you are in terms of riding and handling the bike. My test was supposed to be 45 min, but we were done after a 15 min ride.