Considerably less impressed now. You did say it was %parry/deflect

.
Parry Skill, and Deflect Skill = Weak. It does VERY little for the group. Dirges don't even keep their parry buff up anymore... especially against orange cons. /sigh.
However, I strongly suspect it increases to 17.5 w/5 set bonus (adept III) as it matches the skill. Whoopedy-friggin do.
It just went from "Damn, we got a good deal!" to "Meh, it's epic". And while I like 8% damage reduction (I prefer damage reduction to damage avoidance, as a game mechanic), 20s/5 minutes isn't impressive.