I have the CD+2DVD version of Black Cherry, so I've seen the "Cherry Girl" drama before. It's obviously mostly an excuse to put Koda and her idol friends in a variety of skimpy clothes, but I admit the twist ending surprised me a bit.
I also have the CD+2DVD version of her BEST~second session~ album, and while I don't like every song on either album, I was surprised at the number of songs I did like, especially considering I don't normally listen to that much R&B-style pop. I agree that her vocals are probably stronger than Ayumi -- who has a fairly screechy voice anyway -- though I'm not sure I would agree about being better than Utada.
As for her looks: I don't think she's ugly, but I do think she wears too much makeup...which I admit is part of her whole image. Some of the videos I've seen can be a bit ridiculous and over-the-top, though.