Pros
I liked the actual work when I was put on a route I was comfortable with. There were several routes I enjoyed. I liked routes on foot the most because of exercise and talking to cool people. The old school carriers would give tips and tricks but not too many (because they don't want you to go too fast and ruin the future of the route for others by raising management expectations). So much overtime if that's what you want. I loved seeing wildlife, like a bear in the hills. I liked proving to myself that I could do difficult things, such as carry mail on foot uphill when temps were over 110 during summer. I got satisfaction on days that I was allowed to do a good job.
Cons
If you have integrity, this job will break your heart. When you work as a CCA, you do everything a regular old school carrier does except you do it for longer hours and fewer days off (a merciless "schedule"). You never know when your next day off will be because the Supervisor has ZERO concern about life/work balance. You will be constantly bothered by the Supervisor on your day off to come in, every time. The supervisors have carrying experience on paper but they seem oblivious to your obstacles and have irrational expectations. The irrational expectations drive all carriers mad. New routes can be humiliating, especially delivering to an area saturated with business customers who show no mercy when you dont know their specific delivery preferences and you always get to learn the hard way. The dog problem is 100% fact- I was attacked my first day when my trainer left me alone (and plenty more times. p.s. And I love dogs.) Going on a new route can be overwhelmingly stressful if you care about doing a good job. Supervisor was passive aggressive and petty--she wanted you to feel worthless if you got one over on her for any reason (like the time the schedule said I was off for two days and I made a hotel reservation out of town and she called me while I was packing to tell me my schedule changed and i'm coming in and I said I couldn't because I made reservations--she was so mad, she made threats and made my job harder on purpose after that). People with seniority are untouchable, even the bad supervisors. If you cause trouble by bringing up problems to your Steward too often and the Post Master doesn't like it, she'll transfer you (I saw this happen). The stress was not worth the pay. I experience PTSD whenever I drive by places I delivered and I remember what an awful day it was :(