I picked up the DIY kit from JaxeADV in Netherlands but it was meant to be used in Indonesia where I reside.
Despite my lack of soldering skills, it was surprisingly easier than I thought to assemble with clear instructions. Just make sure you read them fully and several times to avoid mistakes. Makes for a nice little project. Joost was also very responsive in assisting me along the way.
I was able to put the barbuttons to the test very quickly as I used them in a timed rally near Jakarta the following weekend. They worked flawlessly with the Rally Navigator app on Android (also tested with Piste without problems) and did their job of making the rally easier without getting in the way.
I installed them on a KTM Freeride 250F but they will spend most of their time on a KTM 390 Adventure.
In conclusion: no regrets, great value and highly recommended!