Pros
It can be either a great stepping stone while serving your country, or a lifelong career. Either way, If you have a good head on your shoulders, you will learn discipline, work ethic, and how to work with/ lead others.
Cons
The level of fulfillment will likely depend on who you serve with in the day to day. Assuming you enjoy the actual job you chose yourself, your chief, overall chain of command, and coworkers can shape your experience largely because there is a lot of leeway from command to command on how they want to run the mission. You will meet mostly three types of people. Those who do not get paid enough, and the Navy needs more of, those who can do the job but lack maturity, professionalism, or the ability to work with others, and those who do the bare minimum, mentally check out, and with limited personnel assigned per ship to your work center, can cause a disparity in knowledge and work allocated. The Navy has had a clear lack of people joining, and I don't blame them when the quality of life is lower than in the Air Force, for instance. Despite this, I am still forever grateful for how the Navy has forged me personally, the lifelong friendships, and the opportunities available after. I would do it all again, and if you are on the fence, I would say you will definitely not regret joining for at least one contract.
