Do you feel intimidated to submit a mediocre review of a provider who has an overwhelming number of outstanding reviews with scores of 9 and 10?
If the experience was bad for you, recount it honestly. If you are off the mark then the next hobbyist to see the provider will set things right, but if you are on target then you will save some hobbyists the aggravation of doing what you should have done.
If I had a bad experience, I would post it that way. This gives a more balanced view of the provider.
I think it is better to always give an honest account of what truly happened. Besides, I don't trust a provider that never scores below an 8, something suspicious about that. I like to see that she is human and not just a sex machine with perfect repeatabilty each and every time.
Like a lot of things in life, you get what you "pay" for. Translated here that means if the service is poor, the review will indicate same. Granted, tastes differ in appearance and YMMV, but Performance that evening is what is evaluated.