Hikki freakin creates EVERYTHING. She's an actual artist, in the purest sense of the word. If that doesn't spell creativity, I don't know what does.
Ayu is creative, sure. But more than hikki? I don't think so. She just has weird crap going on in her head and she got lucky someone made her a popstar. Her arrangers and composers are creative, and so is avex with its strategies.
So okay, what's this grammy talk stuff? I think she should definitely get a grammy...granted, if she had started in America, and had the same fame proportionate to what she had in Japan...she'd probably already have like a ton.