The best part about it is that it works at full strength even if you have very little mana. Using 10 mana to heal someone for your maximum mana number is an awesome emergency button. Just be prepared to use a mana potion.
I will go to the animal shelter and get you a kitty-cat. I will let you fall in love with that kitty-cat. And then, on some dark, cold night, I will steal away into your home, and PUNCH YOU IN THE FACE.