It's personal pref. I've done a lot of damage testing with recount and it basically comes down to the same DPS with both, since 8 str from thorbia is a lot and the hit/crit from the polished helm is way better for your DPS than the expertise/parry. Interestingly enough the amount of crits you get while crusader is up makes the biggest difference in DPS. I would say crit and str are the best stats. However, recount DPS tests don't always apply to WSG. Having a healer or mage dodge your bloodthirst/heroic strike combo at a critical moment could cost you a life, or the game.
When you gear your warrior you want to consider a few things:
1) Spell hit cap is important because you do not want to miss piercing howl.
2) Hit rating scales upwards because the majority of your damage comes from white hits (as well as most of your rage).
3) Casters cannot dodge while casting.
I would go with the expertise, especially if you are human, and ESPECIALLY if you have a gutterblade. This will mean you have a 0% chance of being dodged by a non-melee class with both weapons. Those with the 8 agi 8 dodge enchant will still dodge your attacks at least 2.75% of the time.