I can say one - this is an amazing wehicle :) I am active person. I have trained for 9 years. I like run and cycling. The halfbike is great connection of these activities. The first use was difficult and more demanding. But the body got used to it after my first eight kilometers. Nowaday, I commute to work. Everyday I can do 8 kilometers on the streets of the city. Sometimes I do offroad near the river :)
I found only one disadvantages. Unfortunatelly, the fender they are too short. The fender in front of halfbike could be longer. Because when I ride after rain or during rain I arrive into drops which are throwed into air by front wheel.