We have quite a few at my club. I sail an RG65 which the dragon 65 is derived from.
The dragon is a racing format and no modifications are allowed, unlike the RG.
The hull is plastic moulding and, but not at my club, there have been some issues of cracks forming by the keel box.
They can be easily carried fully rigged in a car so are ready for the water with minimal setup required when arriving at the water.
They sail well and are easy to get on with.
There are 3or 4 sets of sails available to suit wind conditions.
The current model is version 7. This has changes to the hull thickness is areas, presumably to mitigate the above. The version 7 also has a revised sail winch. If you are buying new supplier should be selling V7 but second hand can be different, also if cheap models offered check the version.
If buying new with radio gear installed go for the FlySky radio. It’s slightly dearer but it is a better radio than the Joysway unit.
HTH.