I had this discussion once with a former lover of mine; his ex had liked him to go at it for hours--actual penetration. Me, I can't stand penetration for that long. I like it hard, fast, and rough. It doesn't take me that long to climax, but I have to have a few minutes at the very least to feel satisfied. It's very, very easy for me to orgasm during intercourse, and after a while, everything starts to get oversensitive. From there, painful sex is just around the corner. That probably starts occurring at about the 15-minute mark.
And sometimes, when I'm barely awake, I like gentle sex. But that's rare.
We're all different, it's true.