So some basic rules I follow in reviewing:
Never give information that is not openly advertised by the SP ie. location of her incall, personal stuff she told you like the fact she has kids or anything that might jeopardize her anonimity.
Don't reveal the fact that you got service that goes beyond what the SP advertises. If she happens to give you a BBBJ, but her ads say safe GFE, then keep mum. Otherwise she will have every fat smelly guy around demanding a condomless hoover.
I will not give a bad review if the SP just seemed to be in a bad emotional state or if she was just not my type. We all have off days at work. I love women in general and can usually find something to like about every one of them. Messy/dirty incalls, misleading advertising, poor hygeine, laziness/unprofessional behavior or bad attitude need to be called out. A scar from a ceasarian does not need to be mentioned in your review.
That said, this site is about information and entertainment and plain old dirty sex. I love reading the penthouse forum style reviews where the guy describes how he slurped vaginal juice and it tasted like evian. How the girls nipples got all hard or how nice and pink her anus was. I have a hard time believing this is not good for an SP's business. Like the other posters said, the girls should be up front with their clients that they do not want to be reviewed if that is their preference.