In reply to Tringa:
It's not. Earlier posts explain this perfectly well.
I joined when I joind the Service in 1072 and it has been invaluable for me, for an operation that i had no chance of having for over a year, for my wife for a couple of treatments that neither the NHS or BUPA would cover and for our daughter for treatment for a distressing illness which the NHS declined to treat and recently for some exploratory work which her London doctor told her that no hospitals in London would do for the foreseeable future.
As far as I'm concerned the many years that I have paid the subscriptios and continue to do so have been worth every penny when the NHS have been unable to respon for varions reasons. Five of ny immediate family work or have worked on the front line in the NHS.
It is under funded, staff are underpaid and there are way too many "managers".
But that's only my opinion.