I think she could dress in a semi-normal manner, but otherwise I think her music is pretty good. Sure, I don't think her music will go down in history as classics but I don't think its bad by any means. But then music is all about personal preference, there is no universal standard for music that all other music can be judged by.
What I've seen of her in interviews she actually seems a bit more grounded and nicer than most other musicians I've seen interviewed. But of course she just might understand the value of good PR.