I fully understand that Roland users like the way Roland allows the user to make changes to style and song tracks including individual changing of drum sound parts on their keyboards, but I don't find the Yamaha way any more difficult. With Roland you press a button, move around to the parts, make your changes and press save. On Yamaha, you move around on the mixer panel, make all your changes and select the digital record style function, hit the 2nd tab button and push save and now you have a custom style or song. Both do the job really well.
I think it's which you get used to. I also find that most of my customers would not get into indidvidual drum map changes but rather select a different kit or just use the one associated with the style.
Kaye's Music Scene