I've been treated at Dana Farber since 2003 and have been operated on twice there and I can tell you they are great. Both Dana Farber (along with the joined at the hip Brigham & Women's hospital) and Mass General are part of Partners Healthcare and I highly respect MGH.
Because they are both in the same system, it's possible that your local hospital is also affiliated with Dana through Partners. Check that out, and if that is the case, I'd go with Dana Farber since they only do cancer and the whole 11th floor (on Jimmy Fund way) is dedicated to Head and Neck Oncology.
I've sent you a private message.

Here's what I've posted before:
Based on my experience having had two operations for oral cancer since 2003, I would like to suggest four thoughts for newcomers.

1) Since oral cancer hits less than 1% of the population, get professional care from a center (CCC) that specializes in cancer and has oral cancer specialists on staff.

2) Don’t hesitate to travel extra hours to such a center-your disease can be life threatening. If distance worries you, see 3 below.

3) Follow-on care may be done at a location which the CCC works with and is nearer to you.

4) Don’t wait to get help, and don’t second guess expert opinion, but if concerned do get a second professional opinion.