I'll tell you all like this:
80-82: Leveled as Ret
82-85: Fuck it, I'm going Prot.
I'm surviving longer, hitting harder and healing better than I was as Ret. Ret is so awkward between procs, cooldowns and damage output. Mt Templars Verdict crit for 9K one time with 3 holy power. My Shield of the Righteous hits for 16K and in some cases 21K.
Sure Vengeance affects the damage output. But I'd rather deal with that than the RNG crap Blizzard thought was good.