The FMA stabiliser better known as FMA Copilot 2 has two sensors, one looks at up/down the other is a horizontal sensor that looks at the horizon. The vertical sensor checks whether aircraft is right way up and corrects if aircraft is upside down, the horizontal sensor monitors aircraft attitude and controls pitch and roll. there is no GPS so it cannot maintain a fixed altitude hover, this would be adjusted by pilot. There are other auto pilot/stabilisers in the market that specialise in that function but as I understand they are aimed mainly at quadcopters etc.
Part of me doesnt want to make flying too easy, the other part of me wants to make it as easy as possible to get flying well on a 'proper' CP heli.
This is where you need to balance what you hope to achieve from flying helis, I find that it helps me to get to grips with the controls and correct any errors I might make quickly enough to save having to open my wallet for replacement parts, so in that respect its a great learning aid. The other use is to maintain stable flight characteristics for helicopter camera platforms, for example, I can fly to and stay in a relatively fixed position for taking airial photos. FMA can also be used in fixed wing aircraft as well so its not limited to helis.
The system I use in my 'Predator' is an FY-21A autopilot, this is a true autopilot and stabiliser which has the added feature of returning the aircraft to point of take off if the it loses signal from the tx. Shame it can't be used in helis.