Currently playing the yellow 6.5 65 in driver, but I go back and forth between that and the black. Both have significantly helped with my control. Used to play the graffaloy blue in an X, but the ball flight was so low that I wouldn't get any roll. I do notice the flight difference between the yellow and black, with the yellow have a much higher launch. Could just be me seeing how the specs are nearly identical between these two. Really wanted to see how the red performs in a fairway wood, but currently playing the PX LZ 6.5 75 in a fairway and feel it's much softer, not as boardy. I would compare the shafts to diamana's line. The kaili plays like the yellow and the ahina/whiteboard plays like the black. Just my two cents though, overall I highly recommend trying these shafts if you can find them for a good price!
Also, be very careful about the flex you choose. I've seen some people get the 6.5 with smooth swing speeds and hit 3/14 fairways. I would say you have to be pretty aggressive or have a quick tempo to play the black, yellow is a tad more forgiving due to the increased flight.