It is difficult to learn, but once it is learned, it is not too difficult to ride. The bike is very portable, fit nicely in the back seat of my sedan. I can take it to go places.
There are a few problems with this design:
1. My model does not have a gear box. It is with much efforts to go up hill, even just slightly slanted..
2. There is no seat so the rider has to stand all the time. It could be tiring.
3. The brake is not too effective, especially when going down hill.