I just cancelled my Payoneer card. I tried to withdraw some cash in Can$ and found out that Payoneer converts my US$ into British pounds and then into Can$. If you make a purchase, even if you were in the USA, a cross-border fee will be imposed.
Besides, there is a monthly fee of $1 or 2 for Payoneer.
At least, when I use Paypal to buy things in the USA, I don't have to pay for the conversion fee or cross-border fee.
So by comparison, Paypal seems better.