I haven't had any problems as of yet I sell on ebay and receive packages almost daily. Im in West Michigan so that might have something to do with it, being less populated but even all my shipments to people have been delivered on time within a few days. May just be lucky I guess.
P.S none of this surprises me I worked at a post office DC in my early 20's for about 2 years and Ive never been around worse workers in my whole life. The place operated as though it was a charity for its workers some making $30 an hour to do almost nothing, that was in the early 2000's. It needed changes then but not sure how it operates today probably hasn't changed much, just my 2 cents.