Hi
Ya know, I consider myself a better than average flyer. I flown hundreds of airplanes, and enjoy 3D Aerobatic very much. I built one of the Sig Ultimates. It is the only Funfly Aerobatic Profiles
I couldn't hover. Erratic is the word to explain it. I gave it away after three flights. And yes, it was straight, balanced, and true.
Maybe I should have played with the setups more. Too late now:-)
Aerodynamically, the stab is too low. The disturbance from the bottom wing make the elevator muddy. I thought this when I was building it but went with the plans because I thought sig knew what they were doing. Check out this sight and look closely
at the stab placement. This guy knows his 3D Airplane designing.
http://www.hokusei-kobe.co.jp/products-ultimate1.htm

A mod like this to the Sig Ultimate, maybe a little longer tail as well (5-10% Longer) would make it controllable in hover.
I'd like to hear the input of other Sig Ultimate owners.

There are many whats to learn to hover. The hard part isn't hovering but finding the way to learn how to hover. Take all the advice you can from all the guys here and any where els you can. Go the the field with a prov-en hover-able airplane, get a few mistakes too high and try different things. The Rudder and elevator are the balancing tools. What I did in the beginning is slow the plane down, power+ elevator to establish vertical, reduce power till the plane comes to a stop. Then full right aileron and power to hold the plane still and balance with the elevator and rudder.

Happy flying, Pat