This is not to start any flames, but to share some info for people who may not be familiar with residency applications, as someone who is going thru the process right now.
after you are an attending, it does not matter whether you are DO or MD or carribean/foreign grad; however, when you apply for residency, non-US MD's are at a disadvantage compared to US MD grads, solely based on title/school location.
many(most?) DO students choose to apply to allopathic residencies as there are very few DO residencies (and out of the DO applicants i've talked to on interview trails, DO residencies seem to be not well liked even among DO grads)
applying to allopathic residencies means not only are you at a disadvantage compared to MD applicants but you also need to take USMLE's in addition to COMLEX. while MD applicants only need to take USMLE's
you generally need better grades/board scores to match into the same residency program as a DO or IMG compared to an MD applicant. It is also extremly difficult for DO's and IMG's to match into very competitive specialties like plastics, derm, radiology, or very competitive institutions like UCSF, hopkins. some residency programs openly state that they do not consider DO's.
many people who do have the stats to get into MD schools will choose MD over DO for this reason alone, and i would say rightfully so, who doesn't want to make life a little easier for themselves down the road?
If you are simply a stellar student who is going to rock your clinical rotations and obliterate the step tests, then you will have no trouble getting into the residency you want regardless of title/school, but this does not apply to the majority.
i personally don't believe there is any difference in the quality of education between the two - i feel what you learn in med school is mostly based on self motivation, but residency programs seem to think so.
infact, since residency programs don't disclose average stats of their residents, often times when applicants want to find less competitive programs, they look for ones with lots of IMGs(international medical grads, carribean grads) and DO's as their current residents.