It depends on a few factors. From my experience, YYJ’s tend to be crafted much better than Duncan’s, but sleep time is all in the throw, bearing being used, weight of the yoyo, and what material the yoyo is made of. Metal and metal-rimmed yoyo’s will spin longer than most plastic models because they are heavier and the weight is concentrated more toward the edges. Both the Kickside and Flying Panda are plastic yoyo’s so I would assume their spin times are roughly even, but the Kickside is most definitely a better yoyo (for 1A at least) in my opinion.