Pros
Partial coverage of medical and dental. Matched contributions to Thrift Savings Plan. Flexible hours, though it may vary by airport. I worked a large airport that is open roughly 20 hours per day, so there were shifts available very early and very late. As a part timer going to school I had few issues working around my school schedule. You will see many weird things. Stable employment, no layoffs during COVID. Many people move on to law enforcement, CBP, and other places from here. Overtime opportunities, but rarely ever mandatory overtime.
Kontras
Pay is not very high. I made a decent amount due to locality, but in a high cost of living area. Can be very stressful. You will encounter very angry passengers. You will feel pressured to make critical decisions in a short amount of time. Some supervisors can be very heavy on the micro-management since following standard operating procedures is emphasized heavily. But the SOP often wont feel like it covers all the weird cases you will encounter. Bureaucracy. It's a government agency, it's huge, decisions are made by levels of management that are far away from your lived experience in the security checkpoint. There is, however, some protection from individual supervisors who don't like you, but only if you can navigate said bureaucracy. There is a union, but you can't strike.