[Bozos of Bones]

Dexterity does not affect how fast you can move.
basically, it's like this. If the target's going to be doing a lot of lockpicking, sneaking or trap disarming, shooting with bows, crossbows or other ranged weapons, or will find himself in alot of Reflex-save situations, then the light armor and high dexterity(16+) are the way to go. If he's going to be a berserker who could just use a bit of a bonus to his reflex save, but isn't overly dependant on it, take medium armor and medium dexterity(14). And if the guy is going to be plain old tanking and dishing out damage by the hundreds, forget all about dexterity, leave it at 10 or 12, and go for the heavy stuff.