but fixed 360 is only good for 2 things - rocket jump and 180 turns.
fixed 2d is what you want for the same 'mousefeel' - which is needed for accurate flickshots
your name is mouse sensitivity, same aim different game, but if the games FOVs are different, you can get very different aim.
also, FOV differences make mouse sensitivities more game appropriate, ie I have a lower cm/360 for quake at 130fov than CS at 90fov with the same mouse feel - this is appropriate for the faster style of play for quake.