I am going to give it a couple of range sessions using what we know of Dr. Kwon's methods. But a couple of things tell me that I won't gain 5 mph right off the bat. My instructor already uses some of Dr. Kwon's methods (or they look very similar) but the Doc explains it in more detail.
I did try using it today. Hit about 200 balls. Did some stage 3, 2, and Stage 1 swings. It took a while to incorporate everything. It took time to grow accustomed to using the obliques instead of swinging the arms and kicking the lead foot. I had a tendency to swing the arms - I think the arms/wrists come in somewhere in the Doc's swing but we haven't heard much. The re-centering was tough - if you did not do that, it was Fat City.
The numbers I saw were similar to what I've been doing with Stack. It will take a few sessions to learn to max out the obliques, etc. and build a new pattern. What I saw on the range with range balls looked like a much higher flight - more spin. The descent angle looked almost straight down in 8-PW. Irons felt more powerful. The driver was more of a mid-high line drive instead of a high flight. We will see. Weather doesn't look good the remainder of the weekend. Need to check the weather for next week.
I've been watching his videos and am starting to incorporate some of it into my exercise thoughts. I do a lot of kettlebell and pull up work. Golf swing tends to get really wrist flipping. I really think this could help.