I started out with a Kit trainer for 3 weeks then the UCD. I did some research and got some SH** info and have paid big time for it. I put the os 50sx hyper(heli) Engine in the 46 UCD. Well the first 10 flights 8 were dead stick because the engine kept choking. I had most of the best members at our field try to gte to run well but only on 30% nitro at $20.00 a gal did it run ok. This engine still was very unreliable. Well finaly dead stick after take off broke my UCD into too meany pieces to rebuild. So I spent some money bought a saito 82 and a Funtana 40. I can do some stuff with the Fun 40 that the UCD will not but is only about half the fun of my old UCD. The UCD is so stable at low speeds and will hover very stable I really miss it alot and regret getting the Funtana 40. I am going to order the 46 UCD tomarrow and sell my 40.