You are likely go get many different responses to this question from pre-meds...however this is my take on it as a first year Osteopathic Medical Student.
Every single course we take is identical w/ the exception of OMM (Osteopathic Manipulative Medicine)....OMM is in addition to all of the other basic sciences such as Pharmacology/Pathology/Microbiology/etc etc etc. OMM is a combination of manual, hands on, teqniques that we learn to treat many common muscular and skeletal pains, conditions, aches, etc. Many aspects of it are used by several other health professionals, such as Physical Therapists, Athletic Trainers and Chiropractors. Keep in mind that for a D.O., OMM is a complimentary form of medicine, as it is used in combination w/ every other standard type of medicine that you are familiar with. Some D.O.'s graduate and go through MD residencies and/or go into a specialty where you would rarely get a chance to use this (ie surgery, dermatology, etc) and thus don't have a chance to use it much in practice and work just like an MD. The Doctors who get to use it the most are the primary care doctors ( ie Family Practice, Pediatrician, Internal Medicine) and several others (Sports Medicine and PM&R.) Some choose to use it a lot, some use it rarely and some not at all.
For the ones that don't use it at all in practice, they still got the benefit of learning anatomy and the biomechanics of the body not just on a cadaver, but also on their live classmates. This aspect of learning aids in the hands on diagnosis of injuries and also the comfort level w/ touching patients.
The only other difference in the education is the emphasis moreso on primary care then specialties. Some MD schools are the same way, but most focus and pride themselves on getting their students into "competative" specialties and many students look down upon primary care. I'm not saying that all MD schools look down upon primary care, but most of my friends at MD schools do. At a DO school, you will likely have to do more rotations in primary care specialties and will have more clinical faculty teaching you that are family practice physicians. In my opinion, it just fosters a different mindset....one where not everything is driven by prestige or making the most money...but on providing quality patient care. That is a huge part of the DO schools' mission statements. (though I may sound like a hippocrite b/c my school, pcom, places 2/3's of their students into specialties outside of primary care).
As far as the lower entrance statistics...think about it. MD is a household name and many pre-medical students are not aware that some Doctors are DO's. People tend to go w/ what they know and assume that anythign different is lesser or inferior. Therefore, many medical school applicants, especially the ones who always had to get the 4.0's and prestige/ego boost from getting what people assume is the best (grades/schools/etc) only go for the MD as they think its the "best". That is understandable, as I did not know what a DO was until my sophomore year in college. It is also a fact that some pre-MD students apply to DO schools solely as a back-up b/c of the somewhat easier entrance stats. That is unfortunate, but is the truth. In the end, everyone regardless of your MCAT/GPA, has to take national board exams and eventually board certification exams...so your college stats count for nothing the day you enter medical school as long as you can pass your med school exams and the national boards.
Wow this was a long one..hope that helps clear some things up...