DO schools traditionally shared a different philosophical approach to treating a patient (whole person, holistic) than an MD, but the two types of schools have merged so closely in terms of teaching/philosophy that there is absolutely no difference in how they treat a patient in terms of patient care and drugs prescribed. I think it now comes down to personally preference more than anything else in how you want to treat a patient.
The only real substantial difference is the OMM stuff which some schools stress while others do not. A family practice doc can perform OMT on their patients and get paid for it. That's about the only real difference in terms of practice.
In other words, there is no educational differences between DOs and MDs, only a historical breach which has brought enimity between the two schools which have been closing in recent decades. Today, you will find DOs in all specialities, in all parts of the country. However, DOs still predominate in the primary cares, in the mid-west and west.
The only thing is, DO grads may be discriminated by some residency directors for competitive programs (and perhaps by employers subtly) in parts of the country like the northeast and california (maybe). And DOs may have a harder time getting into a competitive residencies like derm, rad, ENT.
The former part is because of the 'old school' of thinking in parts of the country, which is disappearing, but won't completely be gone until the doctors educated in the decades past retire. The latter part is because specialities tend to predominate in the MD world and the MD world tend to favor their own students over the DO in some places. However, this is becoming less true (from what I've heard). Also, DO students have their own residencies they can go into, but about 60% of the school I'll be attending do MD residencies (can't give you # for other schools). As far as I know, all DO students match (at least the ones at the school I'm going to have 100% match
), and a majority (50-60%) go into primary care. The rest specialize.
In the end, the difference between the two docs is the OMT, and the focus (so the DOs say) on primary care. Other than that, going to a DO doc will get you the same result as an MD doc---any difference in 'treating the person, not the symptoms' is based on personal taste, not education.