I once discussed this with a parlour girl l knew quite well. She said that if she saw a young muscular guy in a tight t shirt waiting in the lounge her heart sank. She said the younger guys have no technique, just ram it in and pound away at top speed for ages, often leaving her with a sore pussy. For that reason she preferred 40+ guys.
(As an aside she wasn't averse to coming into the lounge post-punt stark naked - usually just for the shock effect. She once came through, naked, and dripping spunk - looked like the end scene of a bukkake vid. "Bloody hell, he must have been saving that up for years!" she said before heading off to the shower. When the punter also emerged five minutes later he was a little wizened old man - looked like Young Mr Grace from 'Are you being served?')