I've built a 4*40- & 4* 60 I loved them both!! Very easy to fly. After ya get used to it you'll find out it will fly inverted as easy as anything!! However I never could get a decent knife edge !!! Unfortunately, both met untimely deaths, the 40 was pilot error, the 60 was knocked out of the sky bya newby (he said,I didn't know that would happen!!) The 40 will give you many hours of fun !!!