I have flown both and did a kit review on the Twist. At low controls, the Twist is like a Stick with a low wing, very easy to fly.

The Twist seems to handle higher speeds better than the UCD. With all planes that have huge control surfaces, you need to be aware that flutter can occur and can be destructive.

The Twist has a slight opposite roll with rudder, while the UCD has directional roll and pitch down.

2 UCD's at my field have had tails break off in flight. One, a .46 size, twice.

The Twist builds a little tail heavy with a .46 and needed a heavy hub to balance. I can't say about the UCD.

The Twist is also not a slouch in 3D. It did everything I could do and is very good at blenders, flat spins, both upright and inverted and forward flips (waterfalls). It is an easy flat spinning son-of-a-gun. It seems like it will hang there for a whole tank.

Just from what I have flown and seen, I would recommend the Twist.