I treat it like any other business transaction, if you don't ask you won't receive. I think that we often expect the "other party" to be a mind reader and get disappointed when they don't anticipate our needs.
Chemistry can't be predicted and at times doesn't matter. Beyond that a lot depends on your predefined expectations. You expect more from a longer higher cost session then from a shorter less expensive session. When you pay a premium and get an average or below average experience then the 1st question you need to ask yourself is did you actively try and manage the experience? If a gal is MSOG and your session appears to be one and done did you ask? If you want CIM and it's "on the menu" and you don't get it...did you ask?
I don't think I've ever walked out of a session without the gal knowing exactly where I stand. 90% of the time I find a gal will go out of her way to accommodate reasonable requests (and the gals get a lot of "requests" that are far from reasonable). I tend to review the very good, very bad or great value. Most of my negative reviews are going to be related to a "lack of" hygene, services or engagement.
Last one I recall (was actually ASPD) and my comment was "a blow up doll at least bounces back at you (or so I assume) and it takes a lot of skill to actually play dead with conviction...but if you've always got off on thoughts of necromancy this is your gal" or something to that effect