I have had problems with FedEx and UPS. Mostly misplaced, delayed and misdelivered packages. Fortunately I have never had to file a claim with either, I hope that day never comes.
I have never lost a package, had a package damaged or had to call, deal with, or yell at a postal worker. Perhaps its a fluke, but USPS has never failed for me, both domestic and international. Plus, if you go into your local post office often enough you get to know them and they get to know you. It doesn't hurt to bring homemade pumpkin bread during Christmas
OT: What I did today: Nailed my presentation at work, the boss was impressed and they want to subscribe to my newsletter. So that's good.