If you are on a budget, you can buy a X3 instead for 200CHF, but Airwheel X8 is more stable and for the price difference, I would get the X8 even if it's your first.
Pro
Good for training your balance and concentration.
15 km range
Rugged
Small enough to carry around in the car or bus or train
Super easy to learn, difficult to master.
Perfect machine for first learning how to ride a electric unicycle.
Much kooler than Segway, and much more practical when you become expert.
Contra
Range could be better
Cannot climb steep slopes
Should have a handle like a luggage trolley handle for transporting without lifting.
Bit heavy to carry by hand. More heavy than the X3
15km/h is a bit too slow. Wish if it went 25km/h
Not suitable for the clumsy people. Requires focus and patience.
inmotion V8 has a better range, speed, and portability.