i'm an osteopathic student.
i think that the difference between a "do" and an "md" is negligible.
however, the difference between a do and an md residency, in my opinion is quite different. do residencies are at small, community based hospitals where you don't get to see variety of cases, therefore you will be less prepared for practice. md residencies are at large hospitals, with excellent teaching. having trained at both do hospitals and md hospitals, i think that the DO hospitals aren't even comparable in quality to the education that you would get an MD program.
note this is just for residencies, the medical education u get as a DO is the same as that you would get at an MD institution.