If you are hired as an RCA, you are only guaranteed you assigned route's days off, so either 1 day a week or 1 every other week. You will be out in terrible weather, trucks don't have A/C and some don't have heating. My office requires to me to work from Black Friday up to and on Christmas Eve with 0 days off. The trucks are not built for the parcel load we get now.
As for co-workers and management, that depends on your office. My current Postmaster is a complete idiot and NEVER should have been given a clipboard. He was only promoted because he would bow to District's will. They rarely promote Clerks or Rural Carriers, so most of management ends up being ex-City Carriers. Did I mention there are THREE different Unions and contracts? Oh and the Rural Union doesn't support their subs, I don't have health insurance, sick days, paid vacation, and am NOT considered Career Employee, so I can't even APPLY to shift elsewhere in the agency.
The job itself can be stressful, packages and mail can become overwhelming, I can't tell you how many times I've been forced to deliver in an unsafe truck, broken frame for example, and just overworked. They pressure you to work Sundays as well so you won't really have a solid day off.
You can make this job have full time hours if you have the Hustle or are "lucky" enough to be in an office that is perpetual chaos.You can work in other offices and get hours that way. You can also transfer to other offices permanently, but you will be on the bottom of the seniority list which is the ONLY way to become a full time employee. So yeah, be warned,