When I did boy/girl porn, afterwards, I think I did improve a little in the bedroom. I learned some new moves and my stamina was built up a little more so that I could spend longer doing certain things, like various types of girl on top. Before, I could only last like 5-10 minutes on top before my legs got tired.
Something you're wrong about is loose vs. tight pussies. That's a myth. Just because a girl has had lots of sex does not mean that she has a looser pussy than a girl who hasn't had as much sex. Vaginas do stretch out to accommodate different penis sizes and of course for birth, but after sex the vagina will return to its original size.
Something else I'd like to point out in reference to hooterlover is that having sex with a porn star isn't necessarily a one night stand. When I did porn, I only had 1 partner outside of videos, and I didn't do that many videos. The guy I was sleeping with on a regular basis was an on-again-off-again type of relationship, but whether we were exclusively dating at any given point, we were still always sleeping together, and we had been dating prior to me doing porn. Oh, and he even made videos with me sometimes! However, your general point that sex with someone you know and care about is typically better, for the reasons you stated, I do agree with.
So all in all, yes, in some aspects, sex with a porn star is better than sex with someone that isn't in porn. Not because of the emotional connection, because there might not always be one whether it's a porn star or not, but because of the moves that a porn star might pull out in the bedroom that a "regular" girl might not do. In other aspects, a porn girl isn't much different than any other girl. Sex in our personal lives is different than sex in porn. In the bedroom in our private lives, we're not putting on a show, we're not having to worry about a camera getting a good angle, we don't have to over exaggerate everything, we don't have a set "script" (direction, as there isn't usually a script in porn, just a general outline verbally given by the director beforehand) so we don't have to worry about changing positions or doing certain things at different points throughout sex, etc. We can be ourselves in our personal lives. There's no camera or audience to show off to, so we're not focused on that, but rather we're more focused on how the sex feels.
So if there is the presumption that a girl that does porn is going to put on a super sexy performance in the bedroom for you, then that's partially a wrong presumption.
Also, porn girls aren't the only girls that know how to do out-of-this world sex. Hell, a girl that's never even heard of porn (haha is that possible? is there anyone out there who hasn't heard of porn?) might whip out some spectacular moves that you'd never expect. It's a case by case situation.
