In addition to above for c of a more paperwork, possible visit to maint org and more cost and involvement of CAA ( things changing, I believe, to rolling yearly checks instead of 3 yrly checks ). Maint work should be carried out by ( or certified by ) licenced engineer ( starting to become rare and expensive ). PFA permit to fly ( as oppossed to CAA permit ) bit less paperwork, cheaper and maint can be carried by Owner and Pfa inspector ( more realistic costs ).