Hey Sessadore,
You're correct on all counts, I was aware of the feat investment in the double weapon, but since I added the double weapon comparison point as an edit after the fact, I didn't feel like running the numbers on a whole set of superior weapons. My main concern in the last analysis was to compare PHB weapon tempest fighters with other PHB weapon fighters, the urgosh comment was an afterthought. I ignored criticals out of laziness
I'm curious how you arrived at two feats for a tempest fighter to use defensive weapons to match the sword and board fighters AC? The only feat I see him needing is proficiency in the desired defensive weapon. Tempest fighters already get two weapon defense as a bonus feat.
I agree with your assertion that feats have to be taken into consideration and applied equally to both sides of a comparison when relevant, but my last post was more about PHB weapons in feat neutral builds.