One point worth noting, is that factory built examples have to be run under a CofA, only home-builts allowed on permit.('Not sure whether both Rollason and Druine are in the same boat).
For some reason this rule doesn't seem to apply to Jodels and Emeraudes, which also give a bit more performance for the power.
Donaldson at the PFA is probably the best to advise on the permit situation.