I use SmartBuff for making sure buffs are up. It can't do more than one if you are in combat (it will do one, then it gets stuck on that one until you get out of combat, Blizzards fault, not addon, won't change). But I only use it for bone shield. I want to use horn for the runic power part, so it want to use it almost every 20 secs no matter what. Costs a GCD and gives 20 runic power, yes please. I also use the extra minute on length of horn so in case I gut buy and forget about it, it is pretty much always up.