I don't have the majority view here. I'd have to say that it's not completely either way. Sure, I agree that it's very heavily weighted toward the student's individual effort, even to the point where I'd say that it's probably like 90/10, but I don't think it's a good idea to discount how a given school helps prepare you for your boards. That 10% won't make you or break you, but it can make a difference in your experience. Not all schools are created equal and not all people are equally suited for a given school's style. If things don't go so well for you for your first two years, I don't care how hard you push it for your board review, it's going to be very hard to catch up (I might know a little something about that). You aren't supposed to be learning new things during your review time, but, if your education is deficient, then that's exactly what you'll be doing and trust me, it's not fun. For example, there are some schools that hardly cover any medical biochemistry and/or genetics and this makes it VERY hard for some without a strong background in these subjects to learn it well enough for the boards. When faced with this sort of situation, you have to either put in more work than usual during your first two years to make up for the lack, or you'll be putting it in when you are doing your review. It's still possible to do really well, of course, with the appropriate effort, but it's just good to know that you'll have to put in more work in certain areas right from the start.
All that said, medical schools tend to be more alike than different and the education is generally pretty equivalent. I would suggest attending the school you feel more comfortable attending as that will probably make it easier for you to learn and perform as well as possible. Having a supportive environment that fits you well is something I think is pretty important, even beyond what is taught specifically. Ideally, it should feel like a collaborative effort.
