I'lll just throw it out there that if you were thinking about running an all tank comp, then my experience is that you're losing out on a substantial amount of DPS, making some encounters harder because of the longer duration. You gain some stability and are forgiven some small mistakes, sure, but personally I found that running 4x Ret and 1x Prot for my pally team was better than all Prot in most encounters. Granted I still had a few ways to reset and cheese some mechanics completely with bubbles and lay on hands.