OP consideration depends on a lot; you can't just look at "ooh, 4-6 healing is too good" in a vacuum. Remember, Guardian Angel heals for about as much, renewable if you keep feeding it light quanta.
Against Fire Shield this would rock for supporting anything but X|1 creatures, like Rustler. Obviously if other creature control sources were in play, like Firestorm, the opponent would want to cast them in bursts to bypass healing and get kill shots. Say you have a couple Rustlers and Cockatrices out, though... a single Firestorm would kill everything 3 and below, and then the Cockatrices would heal back to full in a couple turns.
It's got limited use, but adds some stability to Life.