I had my first experience with the IGyro this month helping Joe Castelao setup his Cougar. It worked pretty much as advertised, but HH on the elevator did not work to keep the aircraft level with flaps deployed. We originally had arrived at 15% up elevator mixed in with flaps to keep the airplane level. Before setting the HH gain, we disabled this additional trim and when flaps were deployed the nose did not hold attitude and dropped. We ended up disabling the HH on elevator and restoring the elevator up trim in the flap system. That was my experience with it.

Now my opinion... I agree that different airplanes are going to need different angles of attack to maintain altitude in different configurations of flap, gear, and airbrake deployment. The HH on elevator can't compensate for all of this unless it also factors in rate of climb/descent as well as airspeed. I don't believe the Igyro does this. On top of that, as soon as you move the stick anywhere off of center, the HH disables and now you are on your own to keep the AoA correct.... well who is disciplined enough to not even breathe on the elevator in order to keep HH active? How do you turn the airplane without adding additional elevator and deactivating HH? Theoretically, the HH would hold the nose up in a turn for you, but in practice it does not. It's possible for certain aircraft types that don't require large trim adjustments with flap deployment to probably get away with using the HH to maintain a rough trim, but it seems to me that it won't be able to compensate for large trim changes that some models require, especially at slow speeds when elevator effectiveness begins to diminish.

Nice piece of gear, but I would stick to using it in rate mode for elevator.

KennyMac