Currently the tier 10 gear for warriors is wonderful. Having two pieces = more aggro. With four, it's more survivability. It's mostly of choice for what you want. Get the item that gives you the best stats. So if you need more health and survivability, get the Corroded Skeleton Key. If you want the set bonus, get tier 10 and etc.
With the new arena season coming out which means a new VoA boss that gives out possible tier 10, I'd say get something else besides tier 10 if you don't mind waiting for the bonus.