The difference between a rapier and a claymore is the difference between precision and power. A rapier can slip between chinks in armor, or through an enemy's guard. Try to block a swing of a claymore with a shield, and you'll be lucky if your arm is merely broken. Both have different fighting styles, but both are very deadly in the hands of someone who knows how to use them. In the hands of an amateur, they're just as useful as a Predator in the hands of a street ganger holding his first gun.