I think its important to take the reviews (positive and negative) with a grain of salt, as there is a bound to be a lot of subjectivity in the reviews of these intimate encounters. When there are two individuals, each with their own stresses, physical attractiveness, background, personality, biases, upbringing etc. its quite likely that even with the best of intentions things could go south (not in a good way). So assume good intent, be graceful, treat the SP with kindness, and even then things may go wrong. Compartmentalize the money and get it out of the way quickly, and enjoy the time together.
If you do meet a person who has not been reviewed kindly, but your experience has been good, be sure to post a positive review to provide balance. And if you see mixed reviews, its worth taking the chance.