Hi ricol,
In answer to your first concern about cancer and metal ions, I think that you might be able to locate some of the long term data you are looking for. While the data on metal on metal resurfacings only goes out about 20 years, I believe that you can find data on metal on metal THRs going out 30+ years as you were hoping. Its been a long time since I looked this up, but I believe there was a long term Swedish study that showed no cancer risk, and overall life expectancy was slightly better than the norm, I am guessing due to higher activity levels. You might also take a look at some of Dr Pritchett's publications. He was around for the first versions of resurfacing back in the 1970s, most of which failed due to the unexpected wear rate of the poly liners. However, there were a few metal and metal resurfacings done back at that time that had good survival rates for the time, and I believe that these might be a source of confirming no cancer correlation over 30+ year periods. The bottom line is that I think that you will find the 30 year MoM data you are looking for if you include MoM THRs and those very early MoM resurfacings in your search.
As for your question about my experience with skiing, I am almost reluctant to post it again because some of the other people on this site have read about it so many times before, but I guess they can just skip this part. If you want a blow by blow description of my experience, I am sure that you can easily find a lot of my older post on this site going back 10 years.
Here is a synopsis. I have been teaching skiing full time (7 hours a day, 7 days a week) in Sun Valley for 48 years, and before that was a racer, freestyle competitor winning a couple of mogul and aerial titles, and film stunt skier appearing in half a dozen ski films. My left hip starting going bad when I was in my 30s, and I put up with the pain and limping until I had it resurfaced by Dr Gross 10 years ago when I was 56. Note that mine is not actually a BHR which is a brand name that Dr Su and many others use, but Dr Gross does not. My resurfacings are both Biomet cementless. Dr Gross allows skiing at six months which put me in mid November. I hiked up the mountain to ski at exactly the six month mark, since the lifts were not yet open for the season. When the lifts did open a few days later, I spent the first hour on the beginner chair to test things out, and then went straight to skiing powder and crud for the rest of the day with no issues. I was a little stiff and sore after skiing for that first few weeks, but on the hill things felt pretty good. I did not start skiing bumps aggressively until about 8 months out, and that went fine. I laying carved trenches on the groomers right from day one, but held off on gates until 8 months just to be safe. Ever since the surgery, I have been very conservative about jumping onto a hard landing, though I am still comfortable dropping small cliffs and cornice drops into powder landings. I finished that first season with a heli trip up to Canada, which I usually do in December, but waited until April that year.
Challenges: I would say that it took about a year to feel totally confident doing one legged exercises like Javelin turns, White Pass turns, Stork turns, etc; no real problems, just some weak glute med and min, as well as rotators. I would say that the hardest thing to get back has been skating. It was definitely uncomfortable for the first three or four years. The pain has gone, but my skating still feels weak, especially skating uphill.
Bottom line; after 10 years on my first resurfacing, I certainly cannot ski like I am 20 or 30, but I would say that it does allow me to ski very strong and aggressively for a 66 year old; on piste, off piste, heli, etc. Next season I am expecting that my second resurfacing that I had done two months ago will allow me to ski even stronger than last year, with less pain and better range of motion.
For what its worth, I have students, as well as fellow coaches, who ski a lot on both resurfacings and THRs. I have found that the skiers I know on resurfacings tend to ski with less concern about any restrictions, but that could be psychological, or due to their doctors advice. I have seen a few cases of THRs dislocating when people bent over to buckle their boots at odd angles, but I think most of those were with the old 28mm heads that were so prone to dislocate. A couple of the strongest skiers I know on THRs had to have them revised after about 15 years, but that was with the older poly liners, so a tough comparison. I have also seen a couple of cases of periprosthetic fractures in skiers with THRs, which I have never seen with a resurfacing. That would be one my biggest concerns, since my non-medical understanding is that stress shielding in THRs often leads to a decrease in bone density in the femur, whereas studies I have read show an increase in bone density with a resurfacing. I have landed hard on mine on ice at 45 mph, with no problems whatsoever.
Standard caveat; this is all just one persons experience, full of non-medically trained opinions, so your mileage may vary. Best of luck in your process.