To the OP and others. I struggled with this same decision as Pre-Med student. My first MCAT was not good but 2nd time I improved like 10 pts just by studying and not being overconfident. My father is a chiropractor who admits he wishes he would have gone to DO or MD and been a physiatrist or FP doc and if DO used OMM and manipulations. I digress, DO was very attractive to me because of that personal background and exposure as a child to a healthcare field that deals with pain, msk, wellness ect. I applied to many DO programs but also many MD programs, and I will be honest because my scores were still a bit low I got more DO invites than MD invites. I was actually set to attend a DO program and got waitlisted at two allopathic (MD) programs in home state where my fiance' was doing her RN training. I got last minute call that someone dropped out of one of the programs and did I want the MD spot, and I chose MD for personal and geographic reasons.
Mayo, Spaulding, RIC, UWashington, ect. all have fair share of DO and MD staff and trainees. As a Mayo senior resident, my class is great mix of DO and MD trained exactly half and half. Our two chiefs are DO. We had MDs match to ACGME Sports, Pain, SCI (even though not match) fellowship top choices (top 1-3 choices) and two DOs match to top 1-2 Pain fellowships. One DO and other MD got very competitive general PM&R jobs at large midwestern health care organizations. I say this because I feel you can be successful in PM&R or medicine despite what road you choose. Ill be honest that I think my DO colleagues had a better MSK experience and knowledge coming into residency than myself or my other MD colleagues, but I am equal to their skills and knowledge now with exception on OMM because I chose to train at a program known to be consistently strong in MSK, sports, pain, outpatient PM&R and things that I was interested in for my training. I think Dr. Zafonte at Harvard/Spaulding is an excellent example that a DO physiatrist can be one of the most well known and respected names in PM&R. Jon Finnoff is another DO that I respect and has mentored me in the sports MSK world and is one of the most well known PM&R docs, in leadership in PM&R and Sports organizations. The list could go on and on.
Know that MD might make an easier road for you because some people do not know what a DO is in areas of country. I see no difference in quality of my DO or MD trained colleagues in the top most competitive areas of PM&R. I think DOs are uniquely attracted to PM&R b/c of holistic approach shared in common, but many MD programs also teach their students to be holistic and to think about mind, body, spiritual issues and whole person as well. Whatever you choose you will be a physician, and if someone does not like the letters behind your name than that is more of a problem with them than you. I still think it is easier to get into DO programs based on scores, letters, experiences, but that is just because smaller number of programs and less known in certain regions what DO is.
Choose wisely. If you want to be PM&R doc, either will be great, and DO very well suited.