Meh! I'm at 1K+ tenacity on my PLD, and my survival rate increased from a defensive perspective. It gives healers more time to dps if they want without worrying about me losing a lot of HP.

I do Tenacity > Determination, but I think I want to put some Direct Hit in there. I'll see when I start buying Verity gear (I have Tomes, but haven't bought anything yet).