Generally speaking, keyboard players have more freedom due to the fact that they have more "keys" as well as the use of a proper mouse. I'm not taking away anything from controller players, but it's expected for keyboard players to outclass them due to the vast variety of options. In essence, M&K has - what I would say- a higher learning curve which brings a higher skill ceiling while controller players can at times have it easier- or rather much more convenient due to the comfortable feel of holding a controller in your hands.