Yes the multi-kings was pretty broken IMO. I don't use ret for progression, just for 3 chesting. They definitely are not nearly as durable as 5 prots, and can be a pita if you take a lot of AoE damage.

I'm around 870+ ilvl on them. My leader (prot) is a bit higher. They're falling behind since 7.1.5 as I've been messing with my hunters and boomies mostly.