The two machines can be told apart simply by the outward appearance. The main differences include weight, size and shape, carry capacity, motor size and tyres. In addition, the FlyboyXL comes in some artistic finishes like skulls, Graffitti and carbon fiber.
So the Flyboy weighs 10 kg and is manageable for a child. The FlyboyXL weighs 15kg and is more of a challenge if it needs to be picked up and carried. The centre at the swivel is also thicker and a child will often battle to get a firm grip when attempting to lift it.
But the main difference is the size of the motors or wheels (the wheels ARE the motors). The next difference is that the XL has inflatable tyres and this allows the rider to venture onto more challenging terrain. The diameter of the wheel and the softer ride allow it to absorb the bumps without any problem. While the FlyboyXL is not designed as an off-road vehicle, it admittedly looks the part and can hold its own on gravel and cobblestones Etc.
The physical size of the battery and rating are the same on the Flyboy, FlyboyXtreme and FlyboyXL.