The UCD .60 is OK as "transitional" plane to full out 3-D. I had 4-5 of them, got them to do almost every 3-d stunt(bad with rolling harriers though)with mixing in spoilerons, fuel tank over CG and a Cline unit. I had OS 1.08 and Moki 1.35 in the .60s, the 1.08 was best, a 1.20OS 2-stroke would be the best IMO. I eventually realized that Great Planes was not going to "Upgrade"(fix) the UCD problems, LG mount too weak for one. I've moved on to 30% gassers, then 33% & 35% gassers, what a difference, great flyers with no mixing, very little trim needed. Finding a .60 size plane that really does all out 3-d is tougher now, Flinton made some really good ones and I had a Fusion that was the best glow 3-d IMO. It ws only around 7lbs w/OS 1.20.
Hey Barry, there is a 35% plane that is capable of rising flat spin-EG MX-2, I saw one do it at my field, the pilot had only been flying for around 2yrs at that point.