[Andrenekoi]

^I will just disagree with the point about maybe Koda being a better performer than BoA. If it's about the dancing, Koda simply has no chance. :B I have a strong dislike for BoA, but is one of the handful pop performers out there who could actually make a living out of just dancing, while a lot of people considered to be dancing legends (Namie, Britney, etc) never really reached that place.

If it's about other aspects of performer than I will not discuss it because I don't really care about Koda as a performer and I am really biased on that.

I also agree people should keep in mind what is the core ability of the artist...

Utada Hikaru is a musician. I expect more interesting music from her than I expect from most.

BoA is a dancer. She releases music so she can perform to them.

Namie Amuro is an entertainer, she also releases music so she can perform to them and keep people entertained during her performance.

I would say Ayu is a storyteller. And most of the time, her artistic choices are based on how she feels the story she is telling will work the best.

The nature of the market will make everyone of them to overlap from their biggest talent in order to stay around, but they will be naturally weaker on areas that aren't theirs. Like asking Celine Dion's level of vocals from Madonna, and Madonna's performance level from Celine Dion.