[quote=Kangaroo]
The other thing to remember about muskets over medieval weaponry is the fear factor, a massed volley of musket fire backed up with extensive cannon bombardment would break the majority of armies, especially those of lesser-developed nations that hadn't experienced it before en masse. Such as Khan :p
[/quote]

Hey we've had some experience of firearms! It wont be as terrible as real life first encounters.

Edit: No No No No No the new world has germs of its own that will kill your settlers too in this case.