I've always used controller. IMO, controller is tops for combat but navigating menus and working out of chests is a pain. that's why I actually use KBM for things like that. I guess I have a hybrid style then. I just HATE using WASD to move. I also use the number row to switch weapons and use potions more quickly. iv'e been pondering getting a separate num pad for this that I can keep closer to my right hand.
going from board to controller might be tough, I dunno. you might think about just getting a board/cushion to put over your lap for KBM while you're on the couch. might be easier that using a game pad