I am, however, a researcher and economist, so for a living I think analytically (and dispassionately) about a lot of things. Being single, I don't have a set time for punting, I don't have to dodge the missus to fit into a time window, I get to punt when I want for how long I want spending as much as I want. I weigh up the pros and cons, and come to a conclusion.
In my opinion the risk of standing at a street corner for last minute directions to get a WG who then feels comfortable and safe is worth the reward of the better service I will get than if she felt unsafe and nervous about me.
Of course prostitution is one of the better examples of an unregulated free market. Both the provider of and seeker of services is free to go where they like, charge what they like and impose any conditions of sale they like. The other party then has the choice as to whether to accept the terms of the deal or not. For Smiths, for example, the lack of an address is a dealbreaker, he won't see a WG without one. That's fine and his condition of sale. The WG has the option of conforming or not, knowing she won't get the business if she doesn't
You're absolutely right, leaving the address until the last minute won't eliminate the risk of being robbed, but, as the posts in this thread say, it does reduce it. Just like how I don't walk around London backstreets at night with my noise-cancelling headphones in. My risk of getting mugged is low (I don't dress well and am a pretty big bloke) but if I can do something easy to lower my risk still further, why shouldn't I do it?