The Proton does look intriguing, but it still has to be produced, assembled, and delivered. The Slinger failed to live up to it's Kickstarter promises (though some still find it a good buy). It remains to be seen whether or not Hydrogen Sports can come through on the delivered product and support.i think Proton machine is better and cheaper and more portable. any advantage of spitfire ?? i don't see one
Also, a lot of these companies fall short in app development. I have experience with a number of apps created for health equipment, sports equipment, smart devices, etc, and they are often pretty terrible apps.