I used Xpresspost. I actually sent it late on Nov.27 and they've just delivered it today around 11:30. I used the address for the courier as per Canada post website tracking. I didn't even see any signature of the one who received it. I guess the lady at the post office forgot to note that I need to see the signature but I'm keeping my faith. You can check it online if you have the tracking number.
For those who still haven't sent your applications and is intending to use Canada Post, I guess you better send it as soon as possible. There will be delays for the delivery about a day or two from the intended delivery date due to the holiday season rush. Better be safe.
Good luck everyone.