16% to armor rating, or a flat 2% damage reduction? With armor being useless against elemental and internal, and subject to armor piercing effects, I'm not sure that the flat 2% might not be better. When I plug in some numbers into the armor DR formula, 16% increase in armor value only translates to about 3% DR with topend armor at level 50... less, up until then.
Of course you could take both, and probably should on a PVE server, but you have some harder choices to make for a PVP build.