Like Moonbeam I would put Bjork well ahead of Tori. My problem with her is the same I have with most singer-songwriters: too much focus on words, not enough on arrangements. I'm sorry, but if you can't write great music to sing to, then I don't give a damn what you have to say.
What are you talkinng about? Have you heard the last Bjork album? You call that arrangement? She has great songs but never classic albums because 4 or 5 songs fall flat are far as arrangements are concerned. Tori has symphonies, harmony and that extraordinary piano. Her writing style is bizarre but dramatic. She doesn't sing about frosty settings or being trapped inside a giant bear. She doesn't make up characters unless she covers them like PJ Harvey either. She's intense and painfully provocative.