I use prot for all my paladins, cant say I've tried ret much but prot seems to die rarely and still blow through levels. Was able to 1-70 in 5 days played, with 1-58 questing and 58-70 instancebuddy, questing as prot and holy for instances. I even have him as prot for 70-80 and leave all my paladins prot for farming for pvp/pve purposes.