Anna,
I am doing the NHSC scholarship and I would recomend it,if working in an underserved area is what you really want to do. I think it would not be worth it for someone who does not have a great desire to do primary care in an undersrved area.
I have always wanted to go into medicine for that reason and I was so excited to get the scholarship. It has been great for me so far, and I am so excited about the opportunites I will have when I graduate and am doing my payback time.
I did the SEARCH program this summer and it was awesome, I had a great expereince and it re-affirmed with me why I wanted to go into medicine. What was also really great about the SEARCH program was that I got to shadow doctors who were doing the type of work that I hope to do when I graduate, it was great to see that it is possible. The doctor's I shadowed also seemed to have a great lifestyle and honestly seemed to really like their job. It was one of the friedliest clinics I have ever been in.
Personally, I never considered the armed forces. Unless you are only looking for a way to pay for school, I don't see the two scholarships as being very similar since the payback requirement is so different. I think the armed forces one may be easier to get, but that's just not a commitment that I could make, seeing as how I have never had any desire to join the armed forces. If joing the Airforce is something you want to do anyways and it is a lifestyle you would like to have, however,then it would probably be a good option for you. I know people who are on the Airforce scholarship and they really like it. I think the Airforce one pays for more books and other required items as well.
I hope this helps.