Originally posted by Kamen Rider
Major difference in weight is because of the number of screws used for these two kit. SD and Pro 4. Pro 4 has a lot less screws than others.
Sounds like it'll be very easy to build and replace parts. I've seen the Yoke, and it took about 20 seconds for my mate to take the rear diff out of it, amazing design, I hope the Pro 4 is the same as this or better.
Also bear in mind that the Pro 4 has all graphite composite parts, whereas the Yoke uses plastic.