I've built and flown both the .40 size (ST .45) and the .60 size (OS .61 SF) with excellent results. The .40 size was a blast to fly at about 5 1/2 lbs dry. If it is snapping on you move the CG forward. I had problems with BOTH of the GP kits being tail heavy and ended up adding quite a bit of nose weight to each before they would fly well. I had almost a POUND of lead bolted under the engine mount in the .60 CAP 21 but it flew very well. It weight about 9 lbs dry and with a 12/6 Zinger, 20% nitro the Long Stroke .61 could just pull it through a tall vertical eight starting from the bottom. You had to hold a little power on to land it but after getting the CG and thrust right it NEVER exhibited any snapping tendencies unless you pulled hard at low speeds. The Caps fly well if set up properly and should be capable of doing every manuever in the book with sufficient power.

You notice that I speak of both the Caps in the past tense. I wore the .40 size Cap out several years ago and after many, many flights I center-punched a steel light pole at our field with the .60-size on a long approach. That's what happens when you fly too late in the day and your depth perception ain't the best in the world. :stupid:

I've also watched a full-size Cap21 doing competition aerobatics and it was impressive. It's an outmoded design now but I disagree with those who say it was a poor flyer.