It has definitely, saved me on more than one clutch occasion.
That said, as a casual player, generally speaking it is kinda underwhelming.
I don't use it 90% of the time, and 90% of the time I do use it, it's unnecessary, or didn't/wouldn't have saved me anyway.
I don't really do much if any savage or higher, but I watch a lot of progs and the like, and "personals" often comes up, so I figure it must have more utility in higher end fights where allowing healers more dps time can be crucial.