I had an opportunity to fly a B407 with the Chelton HeliSAS this week. Quite impressive and a definite safety enhancer. We tried a number of extreme attitude manuevers and found that the system returned the helicopter to straight and level with no drama by simply releasing the cyclic. Handles a coupled approach nicely, which may be useful for IIMC encounters. I have no other experience with helicopter autopilots, but do have substantial airplane AP experience and the HeliSAS seems quite comparable to AP's used in light SMEL airplanes.