About four years ago, I got my hands on a Sky Cat. Or, to give it its full name, a "Sky Cat RCWI Parawing Stunter Kite".
Dating from the 1980s, it's easy to dismiss it as just another Peter Powell clone, but it's definitely not a complete copy. First of all, it doesn't have a cross spar, just a spine and leading edges. Secondly, the frame is much more flexible than that of a Peter Powell. You may think that increased flexibility will make it a rather flimsy kite to fly, the opposite is actually true. It flies very smoothly, the flexible frame absorbing variations in wind speed, needs minimal input, and doesn't oversteer nearly as much as many other dual-line diamond kites of that period.