Hi Wayne.
Unfortunately, you never know if there are design issues with the implants until they've been out for years. That's the gamble.
What is NOT a gamble, but statistically proven, is that surgeon experience plays the most important part of a good, long-term outcome. Probably more so than the device. The generally accepted learning curve for resurfacing is 400 surgeries. Less than that, and they're still figuring it out. That is the FIRST question I would ask your surgeon. I would also ask him for how many revisions he's had, and for what reasons. If he cannot, or won't, provide those answers, then I would question moving forward with him.
I don't know how the NHS works there, but the most experienced surgeons in the world are there, as you probably know. I'm guessing they don't accept NHS anymore?
Anyway, find out his experience level. And good luck.