Showing HP is pretty **** important in healing. I don't know how you guys did it before... but I come from games where I played A LOT of twitch healing for PvP and hp numbers help out a lot. Do you throw a small heal, or big one, fast one or slow one, do you cast more prot on target, what prots do you cast, etc.
I started a low level fvs and it helps a lot. I can decide to turn empower on or off, quicken on or off, what heal to use, etc. I can figure all these questions and take preventive actions before someone taking a big hit and dying because I miscalculated...