Utada's voice is much better than Ayu's. Ayu just has such a huge fanbase thats all. Some of the BEST artists I know are least known, just because an artist is wideknown, dosent mean theyre the best, it just means they're popular thats all.
Beautiful performance. Her voice has much bigger range than Ayus.
EDIT: damn that songs ****ing nice o_o The band is really good!
EDIT2: LOL, that ending gave me goosebumbs