I'm 55 and the only human-powered wheeled conveyances I've ridden have been regular bicycles and (as a kid) old-fashioned roller skates--no skateboards, unicycles, scooters, or in-line skates. So I am still in learning mode on the Halfbike--trying to get my brain to write the new algorithms necessary to really RIDE. Nevertheless, I'm enjoying the learning curve and the comments of neighbors along the lines of "what the heck is THAT thing?"
The only glitch in buying the Halfbike was that my credit card required me to call for a real-time override, since the Halfbike ships from Bulgaria. But once I accomplished that, shipping was very fast and it arrived much sooner than I expected. And assembly was easy with the printed instructions and the custom tool included in the package.
Overall, I give Halfbike a grade of A for making a high-quality product that is giving this middle-aged guy a fun challenge that's unlike any other exercise I've tried.