[quote=@MelonHead]
Ultimately I suppose if there was one sword that outmatched every other in terms of speed in every circumstance there would only be one type of sword that survived the test of time, which is untrue. 
[/quote]

Rapiers can outmatch most other swords in speed, being most dominant in the sphere they were used in. However, that isn't the only factor there is to wielding a sword, so that's why their effectiveness was only limited to unarmored duels.

EDIT: dunno why i posted this, since i'm sure you already knew that :p