I on occasion take either Model Aeroplanes or boats. (not my Avatar, too big).
The planes are not flown on the campsite but my model Corvette or Puffer has provided entertainment on site pools.
The transmitter being shared out amongst the children.
Look it up on youtube (can't post link, internet police, at work!)
They look good fun, I have never seen one before.
What are they like to use and maintain?
There is a gyroscope in the rear wheel which makes them pretty stable. They are robustly made and all the components can be purchased to repair or upgrade. Very little maintenance required.
Pretty easy to use but looks like you need to be really skilled!
I am going into space in a vehicle made from over 3 million components, each manufactured by the lowst bidder - Neil Armstrong