I'd stand by the sentiment though, I'm going to make an assumption that most punters on here wouldn't readily return to a WG who clearly didn't enjoy the encounter unless they a) have cash to burn and don't care how they burn it, b) have no other choice (unlikely given the volume of adverts on AW) or c) they have some need to repeat an encounter, only this time knowingly, with a WG who couldn't cover up the fact that she found it unpleasant.
I don't believe that's true most of the time, because so many field reports tell us otherwise. Whilst many of us do naturally hope for and prefer it when a WG enjoys our company (or the conceit that they might), a sizeable number of reviewers don't seem to be much troubled by this concern, and some underline that they couldn't care less.
'found unpleasant' =/= 'didn't enjoy'. The former would be very unusual, and I'd expect the punter to hear directly about this during the appointment, at least half the time, rather than, as here, having to rely on his own ability to pick up indirect or entirely inadvertent signals. My hunch is that, especially if it concerned someone we had spent time with previously, many of us wouldn't dismiss a WG immediately on the basis of one off-key performance - particularly in the circs the OP describes, where a delicate transition from masseuse to a FS was in prospect for his favourite girl.
In reality, there will be a lot of punts which the WG doesn't enjoy, but they're paid to participate in the fantasy. It's a potential loss of earnings/cause of conflict so they won't do it lightly.
WGs do plenty of things which don't make sense from an ordinary sense of enhancing their earnings, because it's not a normal business.
Contrary to my own argument, just recently I had perhaps the fourth time in my career where I felt sufficiently underwhelmed by a WG's performance that I directly raised it with her on the spot. She'd been blowing to completion, and assumed, or half guessed that I couldn't see that she was merely marking time. Perhaps because it was my first visit to her, and whilst pretty, she didn't seem like a keeper, I wasn't prepared to let it pass, and mentioned that it had made the experience unpleasant … for me. Natch, I shan't be returning. Review to follow within the month.