Not being able to say the difference with the JD kit in the new bikes you must look at the research JD has done in developing these kits. All the WR's have benefitted from these over the years. I remember when these were begun and all the work on this site from him finding the right balance. The difference in the older bikes was phenominal and well worth the money in only the time it saved a person. Go ahead and buy the various jets from the dealer and spend the time making changes, evaluating, and changing again to find what is right for you. Meanwhile people who buy the kit will be enjoying their bike. I tried the other route for about 9 months and then bought the kit for my 99 and it solved all the little headaches for me. I appreciated all the work he did for the owners of these bikes at the time and would buy from him again in a heartbeat just for peace of mind. OK, off my soapbox.