I think I saw a WWS report on the EJ forums that showed iLotP to account for 4% of the raid healing. (From memory, can be wrong) It's not that much, but it helps. Even better if your raid is melee-heavy.
I think it's pretty good if you're a tank, too. As Bear Druids will have high amounts of health, a percent-based heal is pretty good and it will occur nearly every time its CD is up, which turns it into some sort of HoT with 6s ticks... or something. >_>