The reviews already list, in detail, what a provider does, and does not do.  The performance rating should simply measure how well she does it.  If the rating mixes how good it was with what was done it's less useful for the hobbiest.  For example, if I want a REALLY good kiss but don't care about greek and bbbj then I should be able to search for providers that kiss and see performance ratings that are heavily influenced by how well she kisses.  I can't do that now because WHAT the provider does impacts the rating.  Providers who do not kiss as well but do greek and bbbj will probably get a higher rating.  A provider that does everything increadibly well and is wonderful to be with should be able to get a 10 even if everything is covered.  It's not a question of fairness or safety, it's a question of better information for us hobbiests.