*No control over where you live or where your career path with take you. You may have a vision that you would like to work in a certain field, but the Navy will track you where it needs you and there is often little chance to deviate. I was a pilot, which was my first choice, but even as a pilot I did not feel that I had much opportunity to make decisions in my career.
*Little reward or incentive for greater performance. You will go through your first 8 years with timed promotions that keep you in lockstep with your peers. It doesn't matter much if you do very well or mediocre, as long as you are not at the bottom. After about 8 years, you will have a shot at a competitive promotion, but you will still move in absolute lockstep with your peers who are selected also. Don't expect to advance quickly based on superior performance. If you really work hard, it will be rewarded after about 12-14 years with the possibility of commanding a unit, provided your "timing" works out. Timing is a very major component of your career path, and one that you have little control over. It means that the right job happens to be open at the right time. Also, your real competition for good evaluations are generally a very small group of 4-5 peers. Don't think that you will have a chance to compete in a broad group and be recognized for dedication or performance. If you work hard, you will get more work and harder jobs, but it cannot translate to higher pay or more rapid advancement. For some, it does pay off later in their career.
*Absolutely maddening system of bureaucracy for basic things like finding an apartment, enrolling your children in school, or getting a vaccination. I was stationed all over the USA and Japan. The Navy paid lots of money to move me around, but I never had any say or control.
*Your spouse will have a very difficult time having a career. If your spouse has a very portable career, this may work for you. In any case, you need to plan to move every 2-3 years. You may get the chance to stay in one place for more than one set of orders, but don't count on it. You may get 1 year's notice, or you may get 3 months notice after a last minute change.