My ears are burning again.
Thanks for the input on the FMA Bill.
Personally, and this is just my and one other opinion, I do not recommend the Expert gyro. I own one, and one of the guys at the field owns one, with the idea to adjust in the air. No matter what we did, you could not get enough gain for the rudders to be effective enough. Mine is in the box and the other guy returned his.
The Hobbico Multipurpose is a single input and output for the rudders. No, you cannot adjust in the air. The Hobbico Aero can work for single control,but is intended for dual input and output for two channel ailerons and you can adjust in the air.
Both of my P-38's are using both of these gyros, but the P-38, in my opinion is a very extreme case in the event of engine out. It will do an inverted snap roll faster than you can believe.
The gyro for the rudder(s) is to fight yaw. The second for the ailerons is to keep the snap roll, as one wing climbs, undercontrol.
These are not auto pilots, but as c130nut correctly stated, they WILL slow the unexpected yaw down to the level that you can react. The continued damping, will make control much easier. Somewhere in these posts, I discussed my testing with the two gyro set up on a converted ugly stick. If it cannot be found, I can post here again.
Are they, in my opinion, insurance, absolutely. Do I use them on my other five twins, no.
Good Luck,
Twinman