I consistently up my DPS by 25 with my Crit/Determination gear on. I'm gearing entirely with Crit/Determination for i110.
I don't see why you are saying things like 4-5 DPS, because when a Paladin goes from averaging between 80 and 100 up to averaging 125-130, That is a huge boost in overall damage that NEVER stops hitting the boss. Then there are the times when you Off Tank, or Tank Swap, and go into Sword Oath. Your giving yourself a tremendous boost at that point, and every single point in Parry is wasted for that time.
Based on that alone, fights like T6 giving you 50% of the fight NOT getting hit, I would say you are wasting a lot of potential damage.
And FYI, My group has wiped to T6 at EXACTLY .2% Which would have been a kill if I was in my Crit/Determination gear that time.