I rotated in both (2 MD and 1 DO), and found them to be both good at certain things. It seemed at the osteopathic program, it was more learn by doing things. The didactics were a lot less than what the allopathic programs were, but you got to do a lot more. The attendings would always call me over to do procedures, and actually did when I was on off service rotations too. There are not as many residents at the osteopathic programs either, which means it is usually you and the attending working, so you get to see more of the interesting cases. The MD programs had way better didactics, MUCH better didactics. I never had as many procedures as a student (but I am sure this would change as a resident). There were usually more residents working per shift, so you didn't have as much one-on-one teaching, and you had to "share" the interesting cases more.
It mainly depends on what your learning style is on what you decide to do. If you are very motivated to read, learn by seeing things, and don't want to go into academics, then the DO route would be just fine. If you really like great didactics or want to go on for a fellowship/academics, then an osteopathic program probably isn't the best choice.
I doubt that I wil ever want to go into academics, and research is as far away from anything I ever want to do, so I am going into an osteopathic program. It suited my learning stlye the best, and seemed right for me.
Anyone else have other thoughts on this??