I am also deciding between NJMS and OSU... I did not apply to BU. If you look at total cost of attendance, assuming you are living on your own at both schools, OSU is actually $15-$20k less expensive than NJMS over the four years in terms of CoA! That's right, going to OSU as an OOS is less expensive than the least expensive state school in NJ. How cool is that? NJMS also has a block curriculum rather than systems. I hear that going from block curriculum to STEP 1 is harder for many people, compared to those who have been doing systems-based learning from Day 1. But YMMV.
Also, OSU and NJMS are not even close when it comes to quality of life and FUNDING. I work at NJMS every day. It is a school full of really passionate faculty and students and they are all pretty laid back and I like it there, but the funding situation is really dire in some departments. I do not know OSU as well, but I stayed with some current students when I went to interview who were NOT part of the official hosting program. And I got the impression that at OSU, the faculty and students are also very friendly, passionate, and cordial. Like NJMS, I didn't get any sort of gunner vibe. But, unlike NJMS, Ohio State has money pouring out from every orifice and the administration seems like they are dying to spend it on you. Also, Columbus vs Newark?? I don't even need to finish that thought. You know what I mean.
Really, I think you should be deciding between BU and OSU. OSU has made a bunch of adjustments to the new curriculum to build in more time to get the online modules done, in addition to making neuro less nightmarish. OSU has a reputation for fantastic student life and is the least expensive school you will have the option of attending (assuming you are a NJ resident). Don't underestimate that. I know that BU is perhaps more prestigious and they have a "safety net hospital" like NJMS, but that comes with both perks and drawbacks. Please factor in that Columbus is a way, way less expensive city than Boston. I lived in Cambridge for 4 years and I love Boston a lot and it's a great place to live, no doubt. The food is wonderful and the live music scene is very good. But my family was in a much better financial situation when I lived there, so I could afford to actually go out.
I have heard that BU students seem more stressed than students at other places, and I've heard parts of the medical campus (aside from the hospital) are a little old. A lot of that is just from browsing mdapps and reading what others have said on this site, though. But I can tell you firsthand: Boston is awesome especially if you have a lot of $$ to spend, and the same is probably true for BUMC.
I just think you will have a similar quality of life with a lot less debt if you go to OSU vs BU. Actually, I just did the calculation. The cost of attendance difference for four years at BUMC vs OSUMC is $63,780 over four years using both schools' 2013-2014 estimates for M1-M4. If you choose to Pay As You Earn (PAYE), this will likely be $110k+ by the time it gets paid off. If you have a really specific career goal in mind that BU can fulfill in ways that OSU cannot, I guess you should go to BU. But don't be quick to eliminate OSU.
Unfortunately, you can't go to both Second Looks. But I do know that Ohio State is very open to having students come visit at other times during the year if they have been accepted and need to make a decision. In fact, in your acceptance letter is an invitation to contact the admissions office if you want to come stay with some students unofficially. You might consider doing that, and then attending BU's Second Look... or vice versa if BU is willing to do the same. I would try to visit OSU around the same time as Second Look, though (maybe +/- 1 or 2 weeks) so that you can maybe get a copy of what the itinerary would have been.
(Semi-serious side note: Also, you want to go to both schools at similar times to control for climate. The reason the BU Second Look is the last full weekend in April is no coincidence. That weekend, plus the next 2 or 3 weekends afterward, are the times when Boston is "nice", rather than overcast and cold or humid and stifling. When I was at MIT, I remember it snowed the first or second week in May as I was preparing for final exams. It was then that I vowed to leave upon graduation and never return.)