A few of us at my work bought some similar type devices, but with two wheel, like a mini-segway. They are definately more of a toy -- they're a lot of fun to ride around on but not that appropriate for day to day transport. They're actually very stable and intuitive and very easy to get on and off. The learning curve is < 60 seconds. The big issue is that with the small hard wheels small bumps cause it to lurch and can throw you off face first. Had someone with a minor wrist sprain and a fractured elbow basically hitting small bumps and falling off. Would surely not want my grandma using one.