Traditionally, MD has been seen as the safer bet for leaving as many doors open as possible. The historic match rate for US allopathic grads is about 99%, though that's decreased to around 96% in recent years with the proliferation of new DO schools. On the other hand, the match rate for osteopathic grads is around 75%.
There are several reasons for the match rate discrepancy; some are justified, others are outdated. For better or worse, some people both in and out of the medical community regard DO training as "inferior". As a result, DO schools typically have lower average GPA/MCAT scores, which perpetuates the notion that the students are "inferior", and the whole thing becomes a positive feedback loop. DOs have also suffered from having some of their number endorse and promote aspects of the osteopathic philosophy that aren't widely accepted within the larger medical community.
In training, allopathic students take the USMLE and prepare for allopathic residencies. Osteopathic students take the COMLEX in order to match to osteopathic spots; those who want to match to allopathic ones must
also take the USMLE.
My personal impression is that well-trained MDs and well-trained DOs are virtually indistinguishable in practice. I believe there's more variability in the quality of education between DO schools than there is between their allopathic counterparts -- the top end of DO schools is every bit as solid as the large majority of MD schools, but the bottom end is far below the allopathic school floor. That said, I did my residency in the Army, which has a higher proportion of DOs than does the civilian world, and I very rarely had any concerns about any of my DO colleagues. My brother-in-law and my best friend are both DOs, and both of them are outstanding physicians. There are a number of DO residents in my department's residency program, including one of our two chief residents.
In summary:
- Both MD and DO schools turn out excellent graduates
- If you go DO, admission to med school will be somewhat easier but matching to residency may be more challenging
- Like MDs, DOs do residency training in every specialty
With your GPA and a solid MCAT score, you'll be competitive for many MD schools and all DO schools. I think you should plan to apply broadly to both. I'm going to tag
@Goro to this thread, as he can provide you much more insightful and comprehensive information regarding DO admissions and training. I encourage you to read through his post history -- there are a lot of gems there that can help you with both DO and MD applications.