honestly, most people apply to where their stats match up
i'm sure that some people will reply to this post saying "yeah well i have a 34 and a 3.7 but i applied only DO", but the truth of the matter is you apply to schools where you think you have a decent shot
Sure, but there are PLENTY of people who applied to both MD and DO because they had a good shot at both and just made their choice based on which school they liked best. People whose stats were "OK" not amazing by any means, but also not "...I'm sorry, you want to do what with your life?" bad...
I applied to both (at the same time) and then decided based on what I learned/observed about each school which schools I liked better. I happened to wind up at Nova, and I love it. My advice for the OP is to go with your gut. Find the school where you feel the most comfortable. Look for things that matter to you (which may be different things that matter to someone else).
For instance, for me, a big class size 230 wasn't a big deal at all, but for others, it might be. Dissection vs. Non-Dissection anatomy is a big deal for some people. Oddly, it was a HUGE deal for me, and when I found out that NSU did prosection, I nearly pulled out and went somewhere else. I'm really glad I didn't though, I found that I actually really liked prosection. Other things you might consider looking at have been mentioned in this thread already.
The only one I caution you against is "interaction with other interviewees" chances are if you meet someone abrasive that you absolutely can't stand, that they aren't gonna be able to completely hide that from the admissions committee! This goes both ways in that you may meet someone you really get along with well in your interview group (this happened to me at LECOM-B), but there's no guarantee you'd both choose to go there or you'd even both get in there.
Talk to 2nd years at the schools you're looking at MD or DO as much as you can, they have VALUEABLE insights for you as to class dynamics (though they change from year to year). Talk to students about the kind of SUPPORT the school offers (so, really, what does happen if you fail a class? two?) these are important questions that need to be asked...but for the love of God, NOT to the people interviewing you (just a word of caution...I've seen it happen is all).
Location can be a factor for some people. Nova edged out another school for me BARELY because of location. It was closer to home and I like being able to go home some weekends (like this one...for the playoff game GO STEELERS!........anyway...sorry).
I guess what all this rambling comes down to is pick a school, not a degree. You might fall in love with an MD school, if you do GO THERE for goodness sake. If you find a DO school that you feel like is "home" (like I and many of my class mates did) go there! If you have options, consider yourself fortunate and take best advantage of them look at as many places as you get invited to/can afford to see.
Take you time, do your research and make an informed decision. THAT'S how you decide. That's what I did anyway, and it worked out great
Good luck!