S.A.
I work at MGH in the OB clinic and it's a fabulous place w/ wonderful midwives (Not just saying that). I delivered my baby here w/ the midwifery svce. It is a great place to work and the employees all come here. People are happy to work here and help the patients.
I thought the Brigham was kind of busy and not as personal as MGH when my sister delivered her 1st one. She came to MGH for the 2nd and had a great experience. Brigham is a fine place too, but MGH is smaller and much more patient oriented.
I can try to answer more specific questions if you want.
Good luck!