I think that it's because it was for a movie.. :p
While JEWEL is a heartfelt, soothing piano ballad about a loved one..
HEAVEN is singing for a couple that is split apart :< Plus the arrangement had a lot to do with it.. :|
Piano only in JEWEL vs. like.. all the Japanese instruments and strings in HEAVEN with heavy percussion-y ness... yeah it would seem stronger.
But I think the studio track of JEWEL will be just as strong.
