I have both the UCD 40 and the Twist and I like the Twist better although the UCD is a little easier to fly since the longer tail makes it more stable. The Twist is a really nicely made airplane though. I discarded the engine mounts and cut a 1/4" plywood U-shaped motor mount to put the engine on. This makes a very strong nose that can withstand much more abuse than a firewall mount because it ties the sides together with the firewall and engine case. The predecessor Pizzaz had this type of mount up front and I dropped that on the nose several times without tearing out the firewall. I doubt most 3D planes like the UCD would take similar abuse. You'd be surprised how a glow plug can cool down and flameout when the temps get into the 40's during the winter. -Tom