Canada has had plenty of $5 coins over the years.
1912 $5 gold, Montreal Olympics $5 silver slug, Silver Maple Leafs, 1/10 gold maple leafs, and a host of Numismatic coins with the denomination of $5. Only the 1912-14 gold coins circulated to any extent.
We need a modern $5 coin like we need a hole in the head. It serves no usefull purpose unless all the vending machine manufacturers are prepared to use them and spent the millions needed to convert existing machines.
The $5 note serves us well right now.
Rick
(this is part of the previous discussion on the $5 coin)