I moved into the Boston area five years ago and never thought I would stay, so I never took the Boston test, though I have a lot of former coworkers who do work there. They've been there for years and though they've been a medic for my system, they are still basics on the other side of the river. I've heard that Boston has an amazing system and they're training is outstanding. My buddies have said they've learned so much more there than anywhere else they've been and the above is true, it's a constant learning process.
There are many other private ambulance services, but know that if you work BLS, you will probably be doing a lot of transfers. It can be frustrating, but if you look at it as learning, you will do fine. Check into Cataldo or Professional if you want to get some decent experience before going to Boston. Fallon, Armstrong and Lifeline (among many, many others) are around as well and will primarily be doing transfers. Get ready for a paycut, though, because BLS doesn't make much! For a steady Monday through Friday 8-5 job, transfer only but a little better pay, go to Spaulding Ambulance.
Boston is a pretty great city and everyone is right about the driving. I lived in Texas where they drive like complete maniacs and this place blows them way, WAY out of the water!! It's a confusing city to learn as well because it isn't on any sort of grid or pattern...very confusing and easy to get turned around.
A few things to remember when you get here: never, ever look both ways before crossing as cars are watching out for you at all times. Using your blinker is a sign of frailty, and NO one is frail in Boston! Leave off all R's in any sentence, be sure to replace them any place else you so choose, making Law-Lawr...or Melissa-Melisser.
You'll love it here, though. Very cool city & lots to do.