It has been my experiance to always stay away from the girls who advertise in the Pheonix... you never know what you are going to get.  As far as boston TS's Giselle and Coco are the two best looking in my opinion.  They both have ads on eros.

Not that my experience is good with the Boston TSs, but from looking so far, best bet seems to be with visiting TSs.

I once tried to hook up with Coco, but she had me wait about 30 min after driving into Boston.  Call every 15 min, tells me to call back in another 15 min.  After a few calls, she said she left her apt and couldn't see me (had other things to do).  So I called Stasha (turned out she lived only a few blocks away), and experienced my first TS experience.  Unfortunately, it was undesirable, and left me still wanting to experience my first enjoyable encounter with a TS.  One day, a good traveling provider will be in Boston when I have the free time, and it will happen.  But I still think I'll give a local TS a try again.  They just don't have the reviews of some of the visiting TSs though.