Nobody was happy there and you won't be either.
Pros
It kept my bills paid. It's not sedentary. A few people were nice there. I'm a little bit wiser as to why USPS has the abysmal reputation it has. No other pros.
Cons
Abusive, spineless, unprofessional, unfriendly management. There are plenty of other negative words to throw in but all you have to do is Google "USPS CCA" and you'll get the idea. If it weren't for the management this job might be tolerable. There is a culture of us versus them which creates a tension that's pervasive throughout the workplace. It doesn't have to be that way but it is and it makes for a truly dreary job. You see very few smiles from anybody, even the veteran carriers. They're just there for a paycheck and hate their job too. Many are constantly taking pain pills because of the havoc the job has wrought on their bodies over time. I worked two months straight including Sundays during the holiday season until I came down with the flu because they ran me into the ground. This was held against me because I was in my first 90 days. They fired me without a warning or a single writeup five days after Christmas when the holiday peak was over and just a few days before I got union protection. USPS is a dirty, dirty, D-I-R-T-Y institution. I'm so much better off not working for them. Think carefully before applying.