Disclaimer : I graduated from the Brown program 2 years ago.
Brown vs Yale - this was a question I seriously debated when I was applying.
Overall quality of clinical training seems better at Brown including better residents. I agree that research may be a little better at Yale. Yale is also far superior if you are interested in EMS research. Brown on the other hand is in a nicer city, cost of living is less, there is great proximity to Boston and the outdoor activities in New Hampshire / Vermont. Of course if you have a lot of friends in NYC Yale is an obvious choice.
Frankly people that I speak with that are hiring are just less enthused about Yale grads than about Brown grads. Brown has a very well deserved reputation for turning out people that can handle anything you throw at them.
I lived through the residency and now work in a very busy semi-academic ED with very high acuity. The first year out in practice is very scary and I am happy that I got the experience I did at Brown since there is very little you will not have seen when you get out of that residency.