Just to provide some balance here: Even the people who didn't make it in the Federal system very long or left due to frustration I think will still acknowledge that objectively compared to what is out there in private sector the retirement plans are excellent in both Federal and state systems and are rarely ever matched in the private sector.
It is sort of complex depending on your length of service, minimum retirement age, etc. but effectively it works out to either 1% or 1.1% of your average high three salary multiplied by years in service. I'm a vested gov't employee and l will be looking at 40K plus per year just for waking up when I retire by 60. There is also a survivor benefit you can elect which reduces your annuity by 10% so that 50% of your monthly annuity will live on with your spouse after you die. Not going to help me but nice to know my spouse can keep collecting my retirement checks. In addition to this defined pension plan there is also a 401(k) style benefit called TSP referenced above where the government will match 5% on your behalf as long as you contribute at least that same 5%. This can be tax deferred or function like a Roth IRA and it's done pretty well, even recently. Also noted above already, you also take your employees contribution to your healthcare plan into retirement which can be a sizable benefit so you aren't stuck using Medicare as your primary in your golden years. If you are on a second career post-state job that's something to think about.
My best advice: Most of us aren't baby boomers or our parents who have a mentality that "work is work" and spend 40 miserable years working tfor the same company just for the stability and benefits. I think the other posters are valid when they point out that the lifestyle that suits you is key. You've got one life, you've got to enjoy it if you can. That said, working for the Gov't with all the rigidity included is still an extremely popular and sought after option for many psychologists. I certainly make more income in private practice but when I include benefits in that calculation it is not a landslide especially if I stuck to a 40hr work week lifestyle. It is true you have to ask permission to take time off, but it's almost hard for me to take enough vacation to use up all my 8hrs paid annual leave that I get each pay period and 8 hours sick leave per month. Every year I have been here I have received an annual performance bonus (usually not huge less than 2%) for being a top performer. Finally, if it is something you care about most of us are involved in faculty appointments, research or training programs in some capacity. Some folks get loan repayment incentives. I maintain a small consulting and testing practice outside of my day job because I have a flexible work schedule.
Yes, I can make a lot more money in private practice, that's true. But right now I make enough money, enjoy the benefits, well balanced work load, and career stability...even if I have to work a whole 8 hours in a row