Defiance = Grit
Shadowskin = Inner Beast
Shadow Wall = Vengeance
Storm's Path = ???/SoulEater/Abyssal Drain/Reprisal/Darkdance
Dark Passenger > Steel Cyclone

WAR Blood Bath > DRK Blood Bath (longer duration)
WAR Convalescence = DRK Convalescence
WAR Foresight > DRK Foresight (Shorter CD)

No experience for me yet have had groups grumble about DRK tank. And never have I died or party wiped that afterwards we thought, "Ugh, if only Reprisal had proc'd, we would have survived!"