Arch Linux is a limited distro, it's designed to be lightweight. Now if you don't have an old computer, yes it will run faster, but you don't need it. You're better of with a distribution that's got all the features you need, and is something you like and performs well.
Used linux much?
	
 
 as said, Arch can be whatever you want it to be. It is in no way shape or form limited.