Rest is completely unnecessary for this game. Not to mention its incredibly boring.

"OOM. Afk guys, gonna read a chapter in my book while you finish this fight while I /rest for MP."

Ridiculous. Its better if they just put in another MP conservation move, which isn't needed, because then you can continue playing instead of doing absolutely nothing. I've been able to manage my MP very well in every fight both as a healer and DPS.