i think louis worked realy hard with JLS!
but ignored the girl groups ^.^
dannii worked hard with all her acts, and she was able to keep them all half way through the competition
(still ended up losing all of them in a row)
cheryl, i dont think she contributed much with helping her acts, i mean they were already brilliant anyway even if shes wasnt they're mentor! but i think she helped increase the ratings of the show! cuz shes famous
simon i dont think has been as good as he was the other years! if only eoghan wasnt a cute for the girlies, he would have been the first judge to have lost all acts.