Fly the ship...
I find using a joystick and keyboard together greatly increases how quickly I can maneouvre the ship and how accurately I can place the ship in combat. There are only a couple of functions a joystick will control: increase and decrease impulse speed, turn the ship port and starboard, engage warp (1 - 4). I am sure if I programmed it a little I could include other functions like engage reverse impulse or zoom in and out on the console; along with maneouvring and speed change, reverse and zoom are the functions I use most in combat.
I have developed a particular style of flying and without using a joystick, I would have to adapt how I fly as it would be too difficult otherwise. It does allow me to fly in a much more dynamic way (with the help of a good Engineer of course!)