Big fan of the military - as a resource; not in the "Stand for the flag, you commie asshole"/Trumpian sort of way - and while I am not at all a "regret" guy, if there was one regret, it would be not signing the papers when I could have to join the Army National Guard when I was in Georgia. I procrastinated, waffling between being in the Engineering Corps. (undergrad I'm a civil engineer) or in the JAG office, and I ultimately missed the age window. (Even then I was an old fogey).
With the utmost respect - sincerely - to el Barto and his family members, the four branches are not interchangeable. Whereas my experience jibes with what he said, there are other things to consider. A friend of mine was in the Navy, and put his considerable brain power towards the nuclear capabilities in that branch, and now he's out, as an expert in nuclear propulsion systems, he's a well-regarded, and reasonably highly paid employee for an international power transportation firm (one that was recently bought by GE). To some degree, you will be pigeon-holed by what your capabilities are - the military will train you, but if you're good at math, they are likely going to ask you to do some math and not retrain you to be a communications expert - but those capabilities can often be applied in many different directions.
The hardest part, it seems to me, is the first six months. They're going to test your desire to be there, and your desire to be a part of the team. From that, though, it's a relative meritocracy (there's always bullshit wherever you go, but it seems like it's either lesser, or more easily surmounted, depending on your point of view) and as much as anywhere, if you're good at what you do, the people "above you" will want you on their team.
The one piece of advice? You know how on Chris Hansen's crime shows or The Shield they show the cops lying to the perp to get them to talk? Those cops could be recruitment officers. Maybe not OUTRIGHT lies, but they will sell you with whatever you want to hear. You want to be an intelligence officer? They will flood you with stories about being an intelligence officer in Paris, and Munich... and they won't actually be too forthcoming that 1 out of every 1,000 recruits actually become intelligence officers, and of that number, 99% get stationed in the Yongsan Garrison in South Korea (not true, but I'm making a point). Ask a lot of questions, and talk to people to sort of balance out what you might hear from the recruitment officers. Again, it won't be outright lies, but you may not get a complete picture.
I will say this, though, and I recognize that my experience isn't exactly the same as everyone else, but: of the people very close to me that went in, every one of them came out a better person, in the sense of being more disciplined, focused, and motivated. When I met my stepson, he was basically working as an auto mechanic for $12/hr, 40 hours a week, and drinking and vaping the rest of his time away. He met a girl that basically said "I'd be on you like fur on a weasel if you weren't a slack", and so he signed up for the Army Nat'l Guard. Two, three years later, he's working at the local base full-time (quasi-civilian job) servicing helicopters, making almost four times the salary, with full benefits, he's got a beautiful kid, shopping for an engagement ring, fixing and flipping cars on the side... he doesn't have enough hours in the day to do what he wants to do. Now, most of this was HIM, not the Army, but the Army was a sort of catalyst to bust him out of that mindset of "I'm too dumb for college, I don't know anybody, I'm going to be stuck doing half-assed oil changes for old ladies that don't know the first thing about taking care of their cars for the rest of my life... might as well be half lit while I'm doing it..." Similar story for my ex-wife; as much as I don't like her, fair is fair. Being in the AF gave her the tools to be a more successful person.