Thanks for your considered response.
The surgeon I am going to only does hips, and has done a lot of metal on metal hip resurfacing (he said it makes up 5% of his practice) so I am fairly confident in his skill set. He said as far as the surgery goes it is not a trial - it just means picking up the ceramic prosthesis rather than the metal one he has used in the past - the surgery is essentially the same. He also said he has used a lot of ceramic on ceramic THR, so the material isn't a trial either. This particular combination is, though, and he was very clear that there are risks in doing something new. He said all things being equal that one should always go with the tried and true. I think, though, that the advantage of being able to have a THR in the future should I need it, and the advantages of a more natural hip that I have read about are probably worth the risk. Philosophically, too, I realise that someone has to be the guinea pig for these procedures - why shouldn't it be me.
I hope that I don't regret it though!
Great to hear how successful your surgery has been. I can't wait for the pain to be gone and to be able to enjoy activity again.