As I remember, in OFP, when you start using one device to control your vehicle, others (if not touched) are not controlling anything. Now in ArmA, you have all devices active at the same time. Not good, because if I havent zeroed my joystick throttle, I cannot full control with keyboard and mouse. Also I can use full throttle on my joystick and press SHIFT on keyboard - every vehicle goes faster, you can hear it too. So I dont have freedom of choice - there is only one best way of doing it.
Hope this gets done in 1.03.