You seem to have very strong views and everyone to their own, i am not waving the flag for agencies but some of them do look after the girls and do act as agent in the form of taking bookings which saves the the girls a lot of problems in answering phones dealing with clients etc etc and as a client myself i do find that more reliable when i make a booking, at least i know the girl is there or she will show for an out-call and if that fails i will get an explanation as to why..
Do what's best for you Jack, I do !
All about the fun in the end, only problems I have had is bad punts caused by pollution by fan boy reviewers who like to polish turds in their reviews.