Been using the PR and WoP combo for several weeks every now and then (only PvE, exploring Cantha, some missions, etc.). Shadow Arts at 10, Strength at 12-13, <weapon>-mastery at 11-12, only minor runes. With this you get +27 health on almost every hit (adds up very quick), for 27 out of 30 seconds, AND you do high damage almost constantly.
Warrior's Cunning, Signet of Strength, Shroud of Distress, Shadow Refuge and Caltrops (to cripple enemy melees as you engage them) are worthwhile too. Wild Blow for when PR is not up - energy-based attack skill that also triggers WoP and ends an enemy stance.
+20% enchantment mod and major/sup runes can be used to get more out of it..