Gonna disagree on BD and USASG (meh) being particularly busy for Boston ..... best bets are TER, P411 and Eros, BP is actually not bad either, Cityvibe is alright too and adding Boston on your entertainer profile/schedule and using the date-check message board for advertising doesn't hurt either.
Can't recall getting an actual appt from here (ECCIE) but doesn't hurt to use it .
EROS is worse than useless, it's the number one haven for faux providers who want to be paid for the privilege of buying them drinks and dinner. I think it would be cool if provider sites required an explicit full body face picture holding a site-specific and/or contact info card to weed out fakes and leo.