I'm a state government employee who pays into PERA instead of Social Security. When I retire, I won't get Social Security benefits but I'll get PERA benefits if I meet their retirement requirements.
If I retire at 64 with 20 years, I'll receive 50% of my highest 4 years of pay. I can also invest in traditional 401K plans and Roth 401K plans through PERA. I'm fine with the options PERA provides for investment as PERA is not my sole investment tool. As with other pension programs, there are some concerns about certain state PERA programs going broke.
PERA positions are typically state government employees - education, fire, police, medical, etc. I don't know that I can really do a pros and cons list - it is what it is - and I'm not relying or depending on the benefits for my retirement.