Peace Corps is different than Doctors without Borders and has different goals. Having worked as a technical advisor for DwB in S. American and as a Peace Corps volunteer in Africa I actually have a very poor opinion of DwB and a somewhat better opinion of PC. The goals are completely different. A lot of DwB people frankly go mostly as vacations, they live in hotels mostly in large cities where they (literally) drink cocktails by the pool and see very little of the reality of the countries that they live in (in my opinion and experience). They are also paid 5 times or more what local doctors are paid, which in my opinion is morally wrong and also makes the position not "volunteer" though they do make less than they would in US/France/etc.... This is true even for folks who work in Congo (more developed infrastructurally than where I currently live!) or at refugee camps where they are often trucked in from a city for the day's work and do not live at the camp. I see the role of DwB to serve in areas of humanitarian or military crisis....as doctors in refugee camps basically....though this is ONLY putting a bandaid on problems and the "good" of this can be debated ad nauseum....medically treating people who have no social capital or intellectual future is ..........? And flying someone in for 3 or 6 months (the standard DwB service time many places) to do systems development is naive and hurtful. We owe the people we work with better than that.
Folks not willing to dedicate 2 years or more of their lives to ground level work should NOT be doing development planning. Small NGOs, unconsidered financing, and fly-in/fly-out development is literally DESTROYING Africa (like the NGO director here financed by a medium size German aide organization and DED that I, living in the village, have witnessed beating HIV positive individuals so that they will tell the stories he wants heard by funders, raping children, and stealing all the money he is given....the fact that he has a, I kid you not, gold leaf throne in his office might clue out the fly-in/fly out funders....but nope) and caused an epidemic in the town I lived in in S.Am (courtesy of DwB and their genius water dist system that didn't take seasons into account....hmmmm, it was fun when they called me in to fix the problem)
The point of being a PC volunteer is to live in a community at or below the economic level of your contemporaries and to gain a true understanding of the challenges to development. To see stark reality with your own eyes and to make/see mistakes made that you will not duplicate later. Peace Corps also takes the stance of coming into a community, learning, and then applying local solutions. It doesn't always work (often doesn't) but the approach and philosophy is at least different from most Aid organizations which come in and impose external standards and implement plans that were developed in DC or NYC or Geneva in an air conditioned office by people who have never lived in a village (and that includes Host Country nationals working abroad or in their country capitals).
A lot of people don't do PC for those reasons, and think they are going to "save the world" or are just out for adventure....but from my estimation you can do individual good, establish programs and learn a lot of the truth that I believe (as someone with 6 years in international scientific work) most people in development, medicine, and research do not ever come to know. I have acheived "historic" things as a PCV in my country and others have done amazing things as well without an MD: including rotating technology camps, science clubs for girls with 85% university entrance rates, development of functioning anti-traffiking (children) systems, and small victories like getting truly evil people out of funding. Saving people's physical lives is only the very beginning of the problem, if there is nothing to live for, why save someone at all?
An anecdote that I think is enlightening comes from a friend whom I studied with and who is now the WHO director in Cote d'Ivoire. His opinion is that Peace Corps volunteers come to know the realities of countries better than 90% of host country nationals who have finished high school ...because we are there on the ground.
Peace Corps is by no means a perfect organization....FAR from it. But if you really want to learn about the realities of life for the planet's majority, I think it is the only way to do it.
Additionally, I think having an experience of this nature when you are NOT a doctor (read before you have a degree that gives you license to be arrogant and think you know more than the locals) is a powerful thing.
It depends what you want out of the experience and how willing you are to LEARN in the field. PC is a humbling experience and that is the point I think....other experiences do not have this goal I would argue.
If this is a debate you are having with yourself, then talk to a PCV who "Early Terminated" their service (ie didn't finish 2 years) or read the book Village of Waiting by George Packer. Undoubtedly PCVs get more out of the experience than they give tangibly give (the intangible though....), but I would argue that during service and later in their career they help more than they hurt, which I do not believe can be said for much development work.
Also talk to national program directors or aide organization directors who are African/S. America and have field experience. The opinion of PC among these folks is much higher than the opinion of DwB or similar programs in my experience (and I am counting 3 African health ministers, 7 African ministry program directors, 5 WHO directors or section chiefs, and countless international university professors in my informal census ....that made me decide to still do Peace Corps though I did not "need" the experience with my resume).
All international programs are not created equal, so you should chose the one that fits for you.....but make the choice carefully. Good luck and think deep!