Forty-five minutes to an hour is usually ideal for me. But I have always been more into sensual interactive intimacy, me massaging her, cuddling, and intelligent conversation more than the usual sex stuff, which I find mostly boring. I have no interest in oral, etc., and have always been that way, even in my younger days when I could last usually longer than the escort could.
I can only recall once coming from intercourse - Madam Rose's great traveling gal in Phoenix a decade or more ago. After the session, I went to a meet and greet, and an escort who knew my Canadian travels sang "Oh Canada" as I walked in. She sang it great and it was hilarious. The one-hour session had lasted two (the gals option) and Madam Rose when I admitted it said "I knew she was in great hands." Sadly, she died many years ago, but we were great friends.
Many of my favorite times were the old nude-reverse at Allure and 45 minutes was perfect. 90% of the time, I got great moans and "gee, you know what you're doing," and I enjoy giving a massage (Esalen non-sexual but caring sensual) as much as getting it. Now, however, I need a stronger core as I bend too much doing massage on a low table and get back aches quickly in my old age (78 and growing older). Tables are designed for shorter folks, not 6-1 like I am.