The reason their program is shorter is so they can run 2 programs per year. You're paying 5k more for less classroom and case/clinic time.
As for the Boston area teaching institutions, I doubt Mass General or Brigham really want a bunch of pacer students in their labs when they also have EP and cardiology fellows, med students, nursing students, etc.
Also, hospitals and physicians don't just open up their labs or clinics for strangers to come in. ATI has longstanding relationships which make it a lot easier. Hospital access is getting more and more difficult for vendors with RepTrax, Vendormate, VendoClear, etc, and with Joint Commision and other regulatory entitities, I have seen more than a few people escorted out for not having proper ID and credentialing. And these are people who, for the most part, are asked to be there.
It's much easier to get in to see cases in smaller hospitals in outlying areas. You also get better experience in these settings because you're depended on more. The rep is the "expert". You usually have less interaction in a teaching institution because the fellows are asked all of the questions and do the troubleshooting, the rep is just there to run the PSA.
Another thing to consider besides the difficulty getting in to see cases is the difficulty getting to cases. Hopefully PrepMD is focused more outside of Boston than in the city, otherwise, good luck just finding your way there, much less a parking space.
With all that being said, keep all the yankees up there, the last thing we want is more of them in the south. It looks like everyone on their website wants to interview for a job in the Carolinas or Atlanta. No thanks, we're full up down here until half the states of NJ, Ohio, PA, and NY get the hell out.