I'll be the first one to admit that my experience with a paladin has been primarily limited to Holy and Protection builds. I played with Ret a bit when dual specs came out, or when I was running Sheathadin (I've even raided as ret once or twice) - but it's certainly not my bread and butter build.
One thing I really enjoyed was being able to pop SS on myself, and then get crit FoLs off on myself when Art of War procd. It may be that it was due to my healing background, but I didn't see any issue with spending 1 GCD to hit myself with a quick heal while in a party or raid. Granted, my DPS may have suffered occasionally, but it took a touch of strain off the healers and a dead Ret pally's DPS is zero.
Am I Alone?
My question though is, why do I never see Ret pallies casting Sacred Shield on themselves? Looking at the spell, it absorbs a base 500 damage (plus .75 of your spellpower) after you've been struck to actually proc the shield. In patch 3.1 they changed it to benifit from Sheath of Light spellpower, so a Ret paladin with 1000 spellpower will have a shield to absorb 1250 points. Granted, that's not going to help you if Ignis suddenly decides that you're much tastier than the tank, but it will help in the slag pot (or Mimiron phase 2/4).
Is the Ret DPS cycle so tight, or mana such an issue, that using this ability once every 30 seconds is a game breaker? I understand that we all have our roles in the fight; tank, DPS, heal - but come on. Using SS is the equivalent of a preventative Health Pot and Healthstone, without using your potion cooldown. Add in an Art of War instant FoL, which should crit with SS up, and now you've got a Sheath of Light HOT as well.
If I'm wrong, certainly hope someone will let me know, but this seems pretty basic to me. There are certainly enough moments in the fights where you're moving and have a free GCD to refresh the shield.