I don't think anyone really knows how long it will last. There is BHR data for what, twenty years? So you can assume twenty, but you will benefit from all the knowledge gained in how to place and perfect these devices since they hit the scene, so yours may last longer. Your doc will know more and have more experience implanting the BHR than the docs twenty years ago did.
To get real nerdy about this, and I am not a doctor or engineer, so I hope even bigger nerds will join in, there are two problems with the longevity of the device: 1) the device itself, and 2) aseptic loosening, the device's adherence to bone. The devices are getting better and better all the time, both resurf and THR. Whereas they used to wear out in ten-twenty years, now they can last much longer. But that biological part, the loosening, I don't know how much that has changed. Resurf is supposed to do better with loosening. Because the forces are distributed down the bone and in the body in a more natural way, the devices are supposed to stay stuck better and longer.
For a young person like you, this is the leap of faith. You can get worse and worse and put off the operation as long as you can, sacrifice the quality of life you have now hoping it will be better down the road. Or you can go for it. Be better now and choose an uncertain future. Hope that your device lasts thirty-forty years, hope there are improvements when you need a revision. Of course, you also have to consider that you won't live to be ninety. Maybe you get cancer or are in a car wreck. Or to be less dramatic, maybe by allowing yourself to become more sedentary to preserve the hip, your health declines. Your BP goes up, you gain weight, you get diabetes, and so again, you don't live to be ninety.
I was older than you, 53, but a less good candidate as a woman (but a muscular woman). I saw that Dr Gross, my doc, had about eight years of data on patients like me. Eight years out, patients like me had a high 90% rate of success. Those odds looked good. I thought, let's say I get ten years. That puts me in my mid sixties for a revision. In the meantime, I have been very active and been out doing the things I want to do. Mid sixties I am still young enough to do well in a revision, maybe willing to slow down some by then. I do not enjoy the good genetic heritage you have so doubt I'll make it to ninety.
Best of luck. It is a heavy decision. Don't rush into it. Take your time and be sure.