The KitKat approach has some very nice positives. First, the loading / unloading schemes are simpler, thus harder to screw up.
It can be very useful for the masters athlete or someone with a low work capacity. The CF program is very nervous system intensive, and the KitKat program is mentally tough but a little easier on the nervous system at first, but builds a good deal of work capacity quickly. Thus, you will likely be much better able to handle CF style speeds sessions after one or two blocks of a 6 week GPP. ESTI can weigh in here too, but what I learned from him is that it “built a big battery” for his high school kids, and allowed them to tolerate short to long type speed sessions after a GPP.
Remember Charlie’s Short to Long 100m program was for advanced athletes with a massive training base. Many will need a bridge to get there.