Phil,
That's right, as far as i know no competitions allow stabilisation systems. Also all the flying proficiency tests run by the likes of the AMA in the US and the BMFA here in the UK prohibit their use.
I guess it's potentially a controversial subject. With some of today's programmable, stabilised, GPS enabled systems you could quite easily program a heli to fly a basic proficiency test while you sat and drank a cup of coffee and read the newspaper. I'm guessing very soon the technology will be there so you could program a heli to fly an advanced 3D routine fully autonomously. I'm sure no one would consider that acceptable but at what point do you draw the line? The current rules are basically that FBL systems are allowed but they must only be of the type that directly replaces flybar functionality. Any form of artificial stabilising (self leveling), GPS positioning or such like is not permitted.
I dont think this limits FBL development in any way as most people dont fly in competitions. Plus 'self leveling' stabilisation would be counterproductive in most types of flying contest as it limits maneuverability.
F1 is quite a good analogy. They too have struggled with the question of what 'driver aids' should be allowed. I'm not sure what the current rules permit but for sure features like traction control, stability control, active suspension, auto launch control, auto gearboxes are (or have been at some time) banned. These aids are seen to dilute driver skill, to the point where the technology is doing most of the car control.