I can think of two prossies I've fucked who I know supposedly came into the business from the world of swinging...
One I had a very good time with, the other I had a decidedly disappointing time with.
In the world of swinging it's also very different to a punt where the punter essentially calls most of the shots. In swinging a girl could just choose to walk past a big fat hairy bloke and go to the young stud, it could just be for voyeuristic reasons she is there, it also could just be her going with a BF or fuck buddy for exhibitionist reasons. Or maybe she was just there for research reasons, testing the water so to speak...
It's tempting to think to myself, this WG gave me great service because she just loves fucking randoms... But in truth the reality could well just be the total opposite. She might very well not particularly like sex, she could just be very good at putting on an act, and the motivation is financial reward. Personally, I tend to steer more towards thinking the later rather than the former, as I'm fairly sure if the former were that true, most could find casual sex easily enough without turning to prostitution. I also tend to just think, her motivations for being there are hers, and mine are mine, as long as it's something that is happening between two consenting adults and I've had a good time, I don't actually care much beyond that.