I've been in ATC for three years and at age 30 would never want to do anything else. In my former life, I worked in computer networking and at a call center/help desk, and this career has been a Godsend for me.
1. This career is absolutely fulfilling. You are actively responsible for the safety of the flying public, a huge responsibility that makes you go home feeling good at the end of the day. Until I got in this career, I looked forward to every weekend I got. Now, I love my job and love getting to go to work, because I don't feel like I *have* to work.
2. The job market is, unfortunately, not so good right now. There is currently a backlog of new hires in the system that haven't even been processed into facilities yet because of funding and other slowdowns. It took me over two years to get into the career after applying, and that was in the middle of the off-the-street hiring spree that happened in the latter half of the last decade. I lucked out applying/getting in when I did. Now, the military is likely the safest route, as you have a career should the FAA side not work out. That doesn't necessarily happen for those that go to CTI schools, rack up $100k+ debt getting an ATC degree, and think they are guaranteed a job with the FAA only to find out it doesn't work that way, and now they have a degree that doesn't necessarily transfer to other careers. There are occasional postings on USAJOBS.gov, but those are primarily for current federal employees. Every so often, you'll see a posting for CTI or VRA (military vets), but with the glut of new hires in the pipeline, don't expect to see any for a while.
3. I was an off-the-street hire, so I can't help you there. We do have some former Air Force controllers in our ranks, however.
4. Disadvantages/cons. Well, it depends on how you look at it. I have a wife that's a nurse, so we understand each other's weird schedules. If you're into not seeing your spouse or kids often, it's great. We're DINKs for the time being, so the kid factor doesn't come into play, but it does suck to be apart a lot. If you're into hanging out with friends on the weekends, give that up until you have high enough seniority to bid the schedule lines that get weekends off. Expect to have a schedule that puts your days off somewhere in the middle of the week for a little while. It's fun when you can go grocery shopping and do all your errands with short lines in the middle of the week when everyone else is at work, but missing weekend activities can suck. Stress is a given job hazard, but it's all in how you handle what's given to you. Training sucks, plain and simple. It's not really a con, but just an FYI-- you don't get any flight benefits, like free airfare, but for training purposes, we do have a program that lets us fly in the cockpit up to twice a year after a long approval process. Oh, and one potentially big con: you work for the government and are subject to government shutdowns where you won't get paid until everything is running. You're also seen as making too much money as a federal employee, so your benefits and salary are always at risk of being taken away or being frozen, though the union does its best to protect your interests.
5. Advantages/pros. I spent college plus 7 years trying to figure out what I wanted to do with my life, figuring I was doomed to attempting to climb the corporate ladder my whole career, and that was no fun. After I got into ATC, I became the happiest I've ever felt in a job (just ask my wife). Work doesn't come home with you; every day is different; you make fun of your co-workers all day long (and they gladly return the favor; silence in your presence means they don't like you); you have a great salary with great benefits; you work in a career that makes all your friends say, "Wow, that's awesome/must be stressful!"; you have the option of moving "up" to other facilities with higher traffic, or you can move down to a lower traffic facility (and take a potential pay cut); after some seniority, you get to pick who you work with; and you end up speaking a language that is only understood by those in your profession -- which can be a con unless you have a sweet wife that at least seems to pick up on some of it and is quite a trooper when it comes to listening to you talk about planes all day.