Off the top of my head, advantages:
-Very steady and reliable paycheck, no losing income for no-shows etc.
-Very solid leave package; typically 26 days annual leave, 13 sick days, and ~11 holidays
-Good benefits, described above
-The workloads tend to be reasonable
-Good colleagues at least in the systems I've seen
-The vets actually tend to get high quality care in the right systems (PHP, IOP, residential, a range of specialists)
-Generally when you're off you're off. Someone will likely be covering for you
-Often you can get academic appointments and teach, making it semi-academic
-Malpractice coverage is absolutely unparalleled. If you are sued for your VA work you will almost certainly be dropped from the suit and the federal government substituted in. There are rare exceptions to this, such as if you intentionally harm someone.
-No need to worry with the business side of things. Just see patients and cash your paychecks.
-Support systems tend to be good in good systems; for example, if you want a long-acting injection just write the order and there will likely be systems in place to give it.
-Great learning and consultation opportunities, both from colleagues and from services like "ask the expert" where national experts will weigh in on your specific cases.
-Great psychotherapy training through roll-outs if you are interested in that.
-Getting to serve people who otherwise likely could not access mental health care and provide high-quality care without worrying about their ability to pay.
-Getting to serve veterans (you will see some in systems outside of the VA but obviously a lot fewer)
-Once in the VA system you can work in pretty much any setting you can imagine: outpatient, inpatient, residential, specialty clinics, telehealth, etc. etc.
-No non-competes and no real restriction on outside activities as long as there is not a clear conflict of interest. In other works, feel free to start your weekend private practice, forensic practice, consulting role, moonlighting, etc.
Disadvantages:
-The pay tends to be mediocre; private systems often pay meaningfully more (maybe ~50k on average) though likely demand more productivity.
-The bureaucracy can be infuriating. Problems that you identify early on will typically persist for years with no real ability to change them. This will wear away at you, though it depends a bit on your own tolerance for that kind of thing.
-Some staff or, occasionally, colleagues are frankly very bad at their jobs, incompetent, lazy, etc. It is extremely hard to fire them, so you will likely have to just live with it.
-CPRS is actually quite good (the EMR), but the IT systems overall are often very slow and buggy.
-You are paid for your time, so you have to be there. If your afternoon schedule clears, you still need to sit there at work (unlike PP where you can likely just go home). You are also not supposed to take off during the day to run errands etc. Your specific site may care more or less about this.
-The VA dictates what you will do in your job and you take it or leave it. Many policies come down from high up and they often aren't very interested in whether you like it or not.
-The bloat of what is expected seems to grow year after year. For example, documenting suicide risk information for intakes in an intake note, a Columbia suicide risk screening scale, a comprehensive suicide risk evaluation, and a separate suicide safety plan (obviously lots of repetition, and using clumsy templates to scribe it over and over). Again, if you don't like it no one really cares. It just is what it is.
-Some patients can be very entitled, and service connection can complicate the picture (they may fear losing service connected income and benefits if they get better, whether or not this would actually occur)
-If a patient is violent or extremely disruptive, VA still legally has to provide services. That means refusing to care for a veteran entitled to services just isn't going to happen. The VA can choose where and how to deliver the care, but they still have to deliver it. This can lead to nightmare cases such as patients who have stalked and threatened multiple providers continuing to need to be seen.
-The population skews pretty heavily male. There are more female veterans especially from OIF / OEF these days, but you will only be seeing veteran populations.
-There isn't a ton of room for growth. Roles like medical director often give extra responsibility without extra pay (or with a small increase). If you want an administrative/leadership job, that could have more potential for income increase though it would be a lot less clinical.
-To emphasize again, a lot of things will be done the "VA way" which can be clunky, inefficient and even enraging. If you don't like it, it is highly unlikely you will manage to make meaningful change. You need to be able to accept what you cannot change and understand that despite psychiatrists being in-demand, once you sign on with the VA they will really make the final call about what your day to day work looks like.
Overall it's often not a bad job, but you have to weigh out your own personal tolerance for issues like the above and think about what you really want out of work. I would say I recommend VA employment though with some reservations.