I've been riding one for about 6 months now, I'm the Australian importer.
Overall evaluation:
They are an incredible amount of FUN!
The 20" version is squarely aimed at trials riding, the 24" more of a crossover between trials and trail.
2-speed gearbox allows for good trials performance and decent trail speed.
Quality is very good generally (I'm an industrial designer and used to build microlight aircraft for a living). The frame is well built, components are well finished and fit nicely. The choice of components shows attention to getting the best performance and good value.
The motor is brushed, which both minimises cost and also ensures pretty much delay-free throttle response.
The LiPo battery is pretty good it seems - I've put cell monitors on each cell and while they aren't a perfect match they are close and haven't drifted apart significantly over the time I've used it (I ride it usually 3 times a week or more).