|It's been so long since I had my penis in my wife's vagina that I'm probably no longer qualified to answer the question. Back in the days when we were still having regular and frequent sex, my petite wife was quite tight on my above average penis, which was really great. And, having never been in a loose vagina, I can't really answer the question with authority.
I have a Dr. friend that says he always puts in a couple extra stitches following childbirth for the husband. So, those in the medical profession must have either a personal preference that believes they know what's best, or perhaps someone has actually done some kind of survey/research on what husbands and wives prefer, who knows. But it would seem logical to me that; Tight is Right, Loose is no use.