I am PMP certified and having been doing PM work exclusively for the last couple of years. It can be lucrative and sometimes easy but frustrating at times. Like law it is a whole lot of details and "paper work" (almost exclusively online). At the last two financial institutions that I do and did PM work it is night and day. The last one was not all that big (maybe $15 billion total assests) and I felt like a glorified secretary. Minutes up the wazoo, no real established guidelines (they very loosely followed the PMBOK), and lots and lots of meetings. I probably should have just moved my desk to one of the conference rooms. The place I work now is much larger ($250+ billion in assets) and is the complete opposite. Everything is red tape and standardized. And it all has to follow a process. So they seem to be opposite extremes. But everything I do I do by phone so I work one day a week from home (permanent PM's work 3 days a week from home) and they have several that only work from home that live in various locations accross the states.
As for the work, its not too bad. PM's have transitioned from being experts in their subject to being experts in managing other experts to do what needs to be done. I kind of liked being in control of stuff but now it is basically hands off and just keep people meeting their deadlines.
As for money it can be pretty good. Especially once you get your PMP. Some make upwards of $100 to $150 per hour with a few that make upwards of $200/hr. But I think the average is between $40 and $85 an hour unless they are brought on full time where they become salaried employees. There is also the possiblitly to travel and take projects around the country with durations of 3 mos to a year or more.
So all in all it is not a bad career and the pressure isn't really all that bad since most PM's add a bunch of time to their projects and if you always go with the upper range when figuring your budget it is not that hard to keep things on budget. And depending on the company that wants you, you can get some nice perks. I had AA offer to fly me home every weekend from Dallas if I took the project and the rate was $85/hr so it was tempting. And they had residential arrangements that I could have used almost for free.
So the good is that the work can has some pressure, but if you manage the people and get them to do their work, then there is usually not a lot of pressure. You can possibly work from home one to five days a week depending on the employer. The pay gets really nice after you get some experience. The negative is if you don't hire on, your projects are subject to cancelation and your contract terminated (but usually there is another company waiting to take their place). Of course, you are talking gov PM so a lot of the negatives may be gone and I assume the pay will probably be very good.
I went to law school for a year and gave it up for personal reasons but have several friends that did complete it and they complain about having to make billable hours all the time. But if you work in Public Law I have to assume things are probably different for you.
I will say some days I'm torn because my heart is actually in management (IT) more than PM work. I like to be more involved with company decisions, managing and mentoring others, and have a direct effect on the bottom line of the business.
The last thing about PM is that to get certified you have to pass the PMP test which is a tough test but the kicker is that to be able to take the test you have to have between 5 and seven years cumulative of project experience.