I think this is quite an interesting song. In some ways it's a bit cliched but the writing is fairly good in most places. Also, I quite like that it doesn't fanny about with all sorts of 'I was better, she's terrible' things and outright says 'they're a bitch'. The rudeness and bluntness of it is quite refreshing and I think captures the sentiment of the song without being whiny, which is what most songs like this turn out like.