Why such the weak upload?
I don't know; as you can see by the varying speeds you have now encountered, there seems to be some confusion on the available speeds for these Cogeco D2
I still would have expected you would see 1.5M or 2M upload.
I'm not sure that the upcoming 10M upload improvement that jmck mentioned will be made available in a D2 area; but maybe there will be SOME improvement.
Give Start, or one of the others, a call, and try to get what is available clarified. Make sure the CSR is aware you're in a Cogeco D2 area.