Blackcat,
Cooper has a great, friendly group of faculty and residents, and an outstanding PD (Dr. Stahmer) and Chair (Dr. Chansky) who are incredibly enthusiastic about the residency. Ultrasound is taught very comprehensively. They're very supportive of you developing your professional niche and have recently introudcued different tracks (research, teaching, administrative, ultrasound, etc.) for residents to tailor their experiences towards an area of interest. They are very flexible about commitments/problems in your personal life as well. It's a smaller residency with ~7 residents a year at a small but busy, level I trauma center in South Jersey, and they really function like a family. The community affiliate experience provides a nice balance in the patient population and clinical environment. There biggest drawbacks are their lack of name recognition since they're not based out of a huge academic medical center and their lousy location in Camden, NJ, although everyone lives in either the South Jersey suburbs or in Philly.
Beth Israel Deaconess offers a different clinical experience compared to many of the other "Ivy-based" EM programs. The main hospital's ED is big, high-tech, and extremely efficient, perhaps because the faculty are a fee-for-service group. You spend 1-3 months each at 4-5 additional hospital EDs which offers great exposure to different settings, but could be a bit of a hassle. There are some top EM people at BID including Dr. Wolfe, Peter Rosen, and Carlo Rosen, so you'll have opportunitiies to do some interesting acadmeic stuff (textbook chapters, etc.). You do Peds at Boston Children's (top-notch, superacute cases, but there are a million residents rotating through) and at South Shore (community Peds)....no Peds at BIDMC. They have one of the two most active international EM programs (along with Hopkins) if you want to get involved with that stuff. The program's entering their fourth year in existence, but they eem to have already gone through their growing pains. One other drawback is that there seems to be a limited exposure to underserved populations.