Phone number not being displayed is a pain in the arse although that said I tend to e-mail 1st on AW however sometimes it can take quite a while to get a reply (or not get a reply) which is why I tend to find parlours a much more productive use of time in actually getting to see a girl.
Personally I like to get a few details by e-mail and consider whether I still want to punt with the girl, if I get the details by talking to her I feel a bit pressured to agree to book there and then on the phone. One major for me is to get a postcode so that I can check the area on google maps and get a feel for the layout, where to park etc.
One girl gave me a postcode and google maps showed boarded up houses etc so I passed on that offer but i'm amazed at how many girls don't reply to an e-mail asking for a postcode or providing a contact number when requested even though they can see I have good AW feedback.
Now I can understand a girl not giving her full address until a booking is made but a postcode covers about 20-30 houses, also I'm not prepared to book a girl then find she is in a city centre with fuck all parking within half a mile