Speak for yourself!
I wasn't aware that all vaginas were exactly the same and could not take different lengths of cock and different levels of vigorous fucking. I'd like to see your evidence that "9.5 inches may lead to permanent damage and knock on problems" - I'd really like to read those medical papers. So... um... link please?
You are always so quick to step all over people on these boards! I did not say all vaginas were exactly the same! I said
MOST women would be screaming in agony if a full 9.5 was rammed in and there is no way
MOST men would be able to ram the full 9.5 inches in without pain or damage. Where I went to school
most does not (and never did) mean
all. It means
MOST.
The average woman cannot take 9.5 inches fully and rammed home without discomfort - that includes the vast majority of women posting on this site, who have said their ideal penis is 7-8 inches long. Not 9.5. After screwing something that size vigorously, I personally would expect the poster's wife to be exhibiting some tenderness the following day. If she is screwing something like that violently and repeatedly, over a period of time I would expect some cumulative sign that she is. For a woman to get something like that rammed in repeatedly and then to get up and walk around with no pain and no discomfort whatsoever seems unlikely to me. Note - unlikely, not impossible.
My answer focused on potential problems for the woman (which are well documented and may include vaginal tears, cervical bleeding and/or bruising to the urethra and/or cervix). I will leave you to do your own homework and look up the causes of these conditions for yourself (which I am sure you know are well-documented) and which I am sure you know include VIGOROUS SEX. What I will say is REPEATED bruising, tearing and bleeding is more likely to happen when a woman has vigorous sex with a large penis and long term vigorous sex that results in said bruising, tearing and/or bleeding is likely to cause permanent damage (particularly the tearing, which I would expect to form scar tissue within the vagina if it keeps happening in the same place), which in turn could lead to a loss of sensation (and flexibility) in some areas over time. Even if a woman does not bleed, she may end up with internal bruising, which is extremely painful and difficult to get past.
What I failed to mention is vigorous sex can cause a host of problems for the man too. Vigorous sex can be a factor in Peyronies disease (this can affect penises of all sizes) amongst other things. All this info is out there for anyone who is interested in researching this for themselves. But you should also note that I advised the OP to tell his wife to see someone with expert knowledge because I am not a doctor.