It's a poorly designed skill. After playing a priest in WoW, 14's versions of it is just horrible. With 14's low tick rate server, by the time you use rescue the person you're trying to use it on most of the time still gets hit or whatever will happen to them. Rescue is an instant cast but IT'S NOT INSTANT in any way.

I just don't even have it on my bars. It's useless 98% of the time.