The JYD is one of my three favorite folding designs. I've carried the JYDI from Kershaw, The JYD II, the JYD II CB, the JYD II Ti/SG2, the Pro Series Small, and the Pro Series Large. It is such a great knife with the teriffic ergos and the wide blade shape. The flipper works perfectly and the lockup is strong on all of them. The plain model and the CB model are thicker in the handle than all the others. I would definitely choose the CB model over the regular JYD II model. The Ti/SG2 model sits on the top of the heap when it comes to the Kershaw models. It still remains the sharpest knife I've ever had straight from the box. I usually only carry this one now when it comes to the Kershaw models. The only problem I have with the Kershaw models is that clip so I had the clip replaced and converted tip up with an STR deep carry clip. I also sent it to Brad Southard for the addition of an IKBS pivot, a carbon fiber overlay, a carbon fiber backspacer, and a hand satin finished blade. What once was an awesome knife is now absolutely incredible.
The Pro Series are on another level as the IKBS is tuned to perfection on them, the lockup is super solid, the blade is CPM-154 / FFG / stonewashed, and the clip is easy on the eyes and ready to be installed in tip or tip down configuration. The fit and finish on the Pro Series JYDs are, IMHO, on par with CRK knives.