Before I can begin to choose which branch may better suit me, I just wanted to get a feel of the negatives or what needs to be advanced in the field of osteopathic medicine. I figured I would ask here where the students are much more knowledgable.
There isn't any practical difference between osteopathic and allopathic medicine. The differences between the two are predominately historical and there is still some legacy from that divide, which occurred during the dark ages of medicine, in the mid to late 1800's. Essentially, whether you are a DO or an MD, you'll be practicing to a common standard of care in treating patients and unless you use OMT or reveal your degree, patients won't know which you are. So that being said, your question doesn't apply to modern medicine, since there isn't any difference in the way that medicine is practiced between the two degrees, with the exception that all DO's must learn, but not necessary practice (most do not), OMT.
At the risk of starting a horrific and baseless debate on the issue, I think the more appropriate question is, "are there any challenges to being a DO in a professional climate dominated by MD's?" The answer depends on what you care about.
I think the main issue facing DO's right now is that you have two main factions and no consensus. One group is more traditionalist, seeking to maintain, or even accentuate, what few differences remain between MD and DO. Indeed, I'd say that their whole campaign is centered around the "DO difference," "separate, but equal," and all that holistic, "treat the whole patient, not the disease," propaganda rubbish. I'd say that the AOA falls more into that group and since they essentially control the political direction of the profession, some say that they represent a formidable obstacle to change. The other group represents the realists, who know that in this day and age, the difference between the two traditions, osteopathic and allopathic, aren't particularly significant or relevant and that trying to accentuate differences is only serving to keep us down. If you simply observe the professional practice of medicine, it is plainly obvious that there isn't any difference between MD's and DO's, with the exception of OMT, which MD's can learn and practice, too, if they choose. This group seems to understand that, in the tradition of Plessy v. Ferguson, separate is not equal.
You have to understand that DO's are the minority amongst physicians. Naturally this status has associated challenges, some of which center around misunderstanding and confusion about the degree. Although there has been a great deal of education, recognition, and growth of the DO community in the last decade, I think we are going to be minority players for a bit longer and as long as we can't agree on our direction, we are going to be our own worst enemy.
Another significant problem is with osteopathic GME. Right now the trend is that a majority of DO's are choosing ACGME (allopathic) residencies rather than their own, leaving the OPTI's with many unfilled slots. Why? Well, there are two clear ones: the perception that allopathic residencies are of higher quality and that many osteopathic ones are located in geographically undesirable areas.
On top of that, I'd say that the third more signifcant issue is the topic of clerkships and how they are set up at a number of osteopathic medical schools. Right now, most osteopathic medical schools don't have a large, attached, academic hospital, so they farm their 3rd and 4th year rotations to a consortium of hospitals across the nation. Some schools use preceptors that aren't being paid for their role and don't provide a lot of assistance in helping arrange your forth year rotations. Clerkships are very important.
The last issue I'm going to bring up is the topic of rapid growth. As you know, there has been a rapid increase in the number of osteopathic medical schools recently. While there are many positives to that, one of the huge negatives is that you have to balance the increase in the number of graduates with the number of residencies and clerkships available. If you do nothing to increase the number and quality of GME and clerkships, you create a painful bottleneck. I do not support growth at the expense of quality. In particular, I have fears about the for-profit schools that have been showing up recently.
Anyway, I'm going to come off my soap box now and say that either way you go, MD or DO, you'll be a physician and rest assured that, for all practical purposes, there won't be any difference in your practice. You are a physician. Period. You will be defined predominately by how you practice rather than your degree. However, if you decide to go DO, make sure you understand where we stand and perhaps some of the challenges that you might inherit.