They have been officially released in the UK under the brand name "AirWheel". It looks identical to the Solowheel.
I'm very tempted to get one. They are proclaimed to be UK legal ("
AirWheel is the only legal unit of its kind"). The smallest and cheapest unit has the shortest range (6-8 miles) which is a bit shorter than I'd like. Not sure I want stump-up for a more expensive model as a first purchase. A used one for starters would be good until I master it. The most expensive models says it will do 24-28 miles - and actually has 2 wheels -
http://www.theairwheel.com/airwheel).
Has the OP any further comments to share about their experience with the unit?