Have flown and assembled all three. Ka6 the easiest to assemble and easiest to fly, probably one of the nicest handling sailplanes ever built. Skylark 4 more involved to assemble, but very nice to fly, docile, and good climber. SHK wings heavy and require technique, but very manageable with a SoloRigger. The SHK will easily outperform the Ka6 and Skylark 4 . The handling is good, but not as docile as the Ka6 or 4. The Skylark 4 is very capable of all badge distances downwind and is enjoyable to fly. If you are considering buying a Skylark 4 , you should call Bruce Beddow who has owned a 4 for over 20 years.