I can't remember the last time I used AW to actually book a girl. I always mention in my text I found her through AW but they rarely if ever say put a booking through it.
Besides the feedback is a complete waste of time. No one in their right mind is going to give a negative as you'll only blot your own copy book in return.
As for it's effect on service, no it makes no difference to the experience you'll receive good or bad.