Pros
My GS-13 pay starts at $87k and goes to $113k after 20 yrs (unless I get a GS14 spot $103k to 134k, or GS15 $121k to 157k), nicest coworkers and I've ever worked with, 8:00 to 4:30 type hrs, low stress and low layoffs (even if older or with health problems), at GS13 level I deal with companies, 4 weeks vacation a yr, many holidays, good health care, could spring over to other federal agencies (such as FBI or IRS CI), can telework (work 50% to 90% of the time from home). No sales (so no need to spend $100k over 30 yrs on alcohol, or $100k on golf/tennis, or pay to be on boards of nonprofits, or expensive cars or clothes which cost $200k over 30 yrs, no need for dishonest selling or trying to make yourself look better than coworkers, no bullying). Women, minorities, and short people can become mngrs or senior mngrs (don't have to be tall white and good looking). Poor kids from nobody colleges can get hired into federal govt with accounting degrees, but rich kids sent to namebrand colleges with easy degrees can't (unlike many large companies).
Cons
Hard to brag outside of work (white men and women disapprove of you working for the IRS especially in republican states, but minority women are impressed). People in cities with good economies and many large companies view working for the federal govt as a downgrade, but people in small cities or bad economy cities admire you and tell you to never leave the federal govt. Previously GS-13 would retire making a retirement of around $70k per yr for life (a $1.5 million value), but future retirements are less $s and are uncertain. IRS is hiring less now, but they are hiring computer majors in many locations, as well as accounting and attorney positions in Wash DC. At lower GS levels (5,7,and 9s) they have to deal with the hostile general public and small business owners (GS 12 and 13s deal with a larger company's CPAs or attorneys which is less hostile).