Yeah, as an Academy grad, I only recommend going to a service academy if you want to be an officer in that branch.
For me, going to a service academy was one of the best choices I've made. I have a a good paying job, a career I love (helicopter pilot), and no school loans. However, if my goals had been different, it wouldn't have been the same.
As a grad from an American service academy, I feel fairly comfortable in saying, "Go if you want to be in the military." If you join for reasons other than actually wanting to be there, chances are that you'll be pretty miserable. A military career can be an amazing ride, but it can be a bit rough at times.