Neutral review if good service but fully priced, even price is subjective as it is dependent on a punters individual fiscal situation. I would give a neutral review if I receive a good service but then thought overpriced a punter should know the price before booking and hence is not related to the review. They have a choice. Value for money is a bit different because if you pay a low amount they could understand why extra are indeed extra. A higher price would indicate a more inclusive service at the price.
You know the price but you don't always know what you will get for that price. You don't always know in advance about the actual appearance (face, age, dress size, boobs shape, stretch marks etc) unless you punt only with girls with face pictures and non-photoshopped pictures. You also don't always know about the place or actual services unless there exist reliable reviews.
It is actually not very hard to state what good value for money is. Ideally good value for money is very good looks + very good service delivery. Of course I won’t give positive only to girls who are “cheap and good”. If a girl is expensive but both stunningly beautiful and offering very good service the rating must be positive, not neutral. Think of it as rating a car: You can’t rate a Lamborghini “neutrally” because it's expensive.
Available or extra services are irrelevant to me as the absence of OWO, CIM, swallow or anal are not important for me and I won't pay extra if not offered in the “standard package”. Actually many times that OWO and CIM are included in the price I personally choose to not take them and I may instead prefer OW and COB. For me the only “non-standard” service that is often (but not always) a deal breaker is French Kissing with tongue. But each to their own.
Personally when it comes to price I tend to value physical appearance above superb service delivery as I know from experience that at each price range there exist girls who offer an excellent service. So the level of physical attractiveness/beauty and how it compares with the other available options in that price range is what makes the difference. In other words based on a comparison of looks and rates between the available WGs in London (which is the largest pool in UK) I will say that regardless of how excellent the service is that the girl’s attractiveness worth £80, £100, £120, £150, £180, £200, £250, £300+ per hour. A not excellent service is then penalised accordingly by deducting an amount (say £20-£50) from the “looks amount”. Of course my judgment is subjective but anyone who knows me also knows my taste in women.