To be honest, I kind of think these guys are just the balance for the other kinds of guys - lovely, sweet, easy to please! - and they just make me really appreciate my hourly fee.
It's funny because the easier to please a client is, generally the more fun I will have with him and I'll end up going the extra mile because I know I'll get some actual appreciation (and hopefully a nice regular) in return. I'm guessing that's why the perma-grouchy "those money-grubbing whores are all out to get me"-types have so many bad experiences punting; they perhaps forget that their own attitude is so off-putting that they are quite unpleasant to spend time with, even for a paid professional who can try to think about her to-do list til the booking's over!
Or for guys who just want to get their money's worth because they don't have much money to spend and are not getting any sex for free, to be honest, I just again remember that I've got my hourly rate to be thankful for and that it's got to be awful having a sex life comprised entirely of 30, 60, 90, or 120 minute sessions that you feel you have to fill because it'll be ages til you can afford another one. So I stick a big smile on my face, switch positions (and reapply lube!), and give as good a performance as I can. Sometimes I can't help but giggle a bit at the weirdness of it all but often the surprising upside of "gotta fill the session with thrusting!!1!" guys is that they don't expect an intricate and subtle-yet-powerful performance from you; they're happy with a bit of porno "acting" and a genuine smile (so feel free to have a giggle at the weirdness!). After all, they're the ones who are the most acutely aware of the artificiality of the situation (since they have the minutes counting down in their head), so they don't tend to need you to fawn and snuggle and tell them that you've experienced a genuine connection blah blah. That can be a relief after a series of clients who've needed a lot of constant emotional reassurance.
Jodie's post made me ponder something. There's that point during any appointment that can occur where the guy's been thrusting away for a while and you both start silently wondering whether the other is enjoying it, which means you both basically start to get a bit awkward and the whole thing starts to become a bit unconvincing. This can happen with any nice client, unfortunately - he wants to hold back a bit "for your pleasure" (and also so he doesn't "let himself down" etc etc), but then you cross over to the point where you're both just looking at each other and thinking, "What's (s)he thinking? Am I doing it right?" I'm guessing that's the part where a little extra, i.e. some super-hot dirty talk, is needed! And once again I remind myself to get good at dirty-talking because oh em gee I'm STILL so terrible at it! Must practice in front of the mirror.