After orientation and a bit of balance training the group I was in followed the instructor as we spent a good hour or so travelling down muddy tracks and across country fields.
For my part, I enjoyed the experience, and I could certainly see the appeal of using one off-road[2] and would have happily spent my weekends on one in the countryside. On the road/pavement, they had much less appeal as they were bulky and hard to steer nimbly in crowded areas.
As we know they were an important first step to self-balancing vehicles/robots so we shouldn't judge them too harshly; many initial inventions fail, just to be reborn years later as an improved concept.
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[1] The horse kind, not the keyboard-warrior kind.
[2] These Segways were fitted out with larger off-road tyres compared to the ones you usually see.