That would be a first for a poster with that handle from Gozo (if indeed you really are).
Although I have nothing to add about the PPU's representation at an individual level, surely joining a union is only of wider use if you think there is any prospect of that union being recognised by your employer for collective bargaining. With BALPA recognised by a good many UK airlines, there seem to be few openings where the PPU could hope to become the recognised union. If it is just going to challenge BALPA, TU laws in the UK don't provide for a recognised union to be de-recognised, so this will simply result in today's stalemate on recognition in V/Atl being replicated across all UK airlines. It's not exactly a step change in industrial relations.