Someone brought up the same question on the RVU forum because RVU is opening up a school in Utah.
Strictly talking about the student experience, I think it would make a difference. Not sure about other DO schools, so I'll just talk about my experience as a first year at RVU-CO. Having the upperclassmen around is really helpful. At the beginning of the year, we get paired up with second year mentors that will help us with anything we need. We also meet up before each course and they will give us advice on how to do well in that course. We have free tutoring from the second years for all of our courses as well (they have to be top students in that course from the previous year). They share tips and go over high yield topics that the specific professor really focuses on. (The tutors get paid by the school and it's free for students to make appts with them). The previous years' students also share resources such as study guides, notes, drawings, etc. Those have been TREMENDOUSLY helpful! Right now we are in our musculoskeletal system course and not only do we have 2nd year tutors, but we also have anatomy fellows (3rd and 4th year students) helping us with dissections, along with the professors and faculty. Also, we have a weekly and test review for every test and every course. These come from the 2nd year tutors and they make up questions that will be similar to what we might see on the exam and essentially quiz us (usually iClicker format) and then go over why an answer is wrong or right (they also send those out for people who would rather look at those questions without attending the session).
I also know that recently, the 3rd years came back and talked to people about what rotations are like. Tips on which are the good or bad rotations, or which ones are harder and easier, and what you can expect from the different rotations, etc.
I don't know much about BCOMs curriculum or research, so I won't comment on that. But, from a student's perspective with courses there's only so much help a student can get from the professor. I'm sure the first graduating class will be fine, but you do have to work extra hard if you are the first graduating class since there's no one to help you. If you like the school enough, maybe these things won't matter to you. But since no one has brought it up yet, thought I'd share my thoughts on it.
Also, it's important to keep in mind that especially as the first matriculating class, you MIGHT not do well on the boards. Your rotations MIGHT not be good. There's no guarantee. Just because the school is going to kinda copy RVU's doesn't guarantee good board scores. There's a lot of resources that we have at RVU that a school won't have yet. Also, the faculty are not the same, etc. When you go to a new school, you are taking a HUGE chance.