Hi dfree 86,
I used this forum last year for the same questions, and didn't get any good answers, so I hope I can help. I am finishing up my Ed.M. at HGSE right now, and went through the same thought process as you did when it came to selecting school last year.
To cut to the chase: I have been fairly disappointed with the Master's program here. While not in the same focus area as you (I am in the Mind, Brain, and Education program), I have heard similar complaints across the board. The Ed school has faced the same budget constraints of other universities during the recession, and thus has doubled the size of incoming Master's classes, without adding faculty or staff. I have only had one class that had less than 25 people in it, and it was technically through the Kennedy school of government, not the Ed school. I also have yet to have a face to face conversation with my advisor this year. So while the name is flashy (at least once you are outside of Boston), I would strongly urge you to go with the program that you know to be of the highest quality (which sounds like TC from your description) rather than the flashy name.
Hope this helps!