I don't see how it's any more powerful than WAR's sustain/self healing or GNB? I've ran dungeons with WARs and GNBs where I swear their health wasn't moving or if it did it went back to full health almost instantly and it wasn't cause of me.

I also like that when I play PLD I can heal myself when the healer is uh...way below "average" which happens a lot.