Musically, Babymetal is basically their backing band (Kami Band) IMO, and they are obviously very good. The idol/dancing aspect is why I personally could never get into Babymetal, that's just not my thing.
I do like their singing, but the idol stuff definitely leaves a bit of a weird taste. Idol industry is pretty bad in terms of how it treats the idols (though AFAIK the Japanese are slightly better about this than the Koreans).