I have applied to both MD and DO this cycle and have been accepted to a DO school, so I'll give you my opinion on it.
Since there are more allopathic residency spots, especially in the specialty area, a lot of students in my accepted school take the USMLE on top of the COMLEX. That's 2 exams you have to prepare for, which are less than a month apart. So that is 1 qualm I have about a DO school.
Also, DO's are not internationally recognized as MDs and thus cannot practice in certain countries. If you're looking into going abroad to practice in the future, a DO degree will likely hold you back, especially if you want to go to East Asia or Western Europe.
Since DO schools teach OMM, this is one more thing that you need to study on top of the basic sciences. Generally, it is 1 hour of lecture and at least 2 hours of lab work per week. In my accepted school, it's a total of 4 hours a week.
These are the general obstacles that faces a DO student that an MD student does not need to worry about. The rest, such as curriculum, facilities, faculty, research, rotations, etc are purely school-related, so I suggest you research the school: If you want P/F instead of letter grade, for example.
Good luck