This topic has not had any replies, perhaps not of interest.  But my curiosity got the best of me so I pulled the trigger and called.  Met up with a provider in western MA whose name I did not get (does it ever matter?).   It was a very good experience.  I met a provider in a low-end motel chain room who was pleasant, attractive, and very accommodating.  

There is always a "boss" somewhere in the background who generally answers the texts or calls.  They may or may not be onsite.  I asked for a picture, which was sent, but the provider was not the one in the photo.  No matter - she was attractive but not stunning.  The ad in STG promises a choice of girls, and shows multiple photos, none of which are likely providers actually available.

Everything was on the table and available.  Nice massage followed by BBBJ and BBFS.  She knew what she was doing, and unlike my previous experience with a similar set up about 4 years ago, this one seemed to be enjoying herself.  I suspect the next encounter might be quite different.  These girls rotate and I am sure this one would not be there next time I might call.

That's how they work although I've never gotten BB anything. I used to see them all the time but the service varies a lot. If you don't like whats hiding behind the door just leave.  I personally think it's better experience, if you have the time, to drive up to Brattleboro  or down to New Haven and visit an AMP.