First, never believe how many hours a person says they study. Most people are totally inaccurate, even when reporting to themselves how many hours they put in. There are people who say they never study, then you find them hiding in a back corner of the library secretly studying. Then there are people who say they study 12 hours a day and you find them in the library sleeping on top of their books all the time, or at the coffee shop talking to everyone who walks by while they have their books out in front of them, thinking they are studying the whole time. Each person is different and has their own habits, and you will have to find what works with you.
The cirruculums and difficulty is SO similar among US med schools, becuase it has to be if we all want to pass the USMLE exams.
What is different is the attitudes of students about having a real life. Pay attention on interviews to if student look happy and ask them what they do in their free time. Find a place that fits for what you want out of life.
I'll put in a plug for Tulane, while I'm at it. Everyone agrees that while we work hard, we also play hard when we have the time. Most students work out regularly(exept maybe the week of exams), and most students make time to do something fun at least one or two days a week - whether it's a movie, dinner, party, all-night bar-hopping-it IS in New Orleans(where bars are open 24hours and there are something like 300 festivals and fairs in this state every year). In the first two years, students are encouraged to participate in community service clubs, intramural sports, and the arts. Students sponsor art shows, play music in bands, run marathons, ect. Everyone gets stressed out at times, and no one would say our school is easy - far from it. But living a balanced life is the norm most of the time. And in the end, we get into very competetive residencies just like all the other good schools where students never have fun. In fact, we might get some better residencies because we are more than just bookish nerds who do nothing but research in our free time. Check us out. Good luck to you.