> Well, USPS has demonstrated itself to be unreliable, so there might not be much of a > choice.
Over the last 20 years I've sent thousands of packages via USPS and the number that have been lost or damaged I could count on one hand. But a .001% failure rate is "unreliable" in your mind?
Everyone notices when a service fails but nobody pays attention to the dozens/hundreds/thousands of times when everything works the way it should. The USPS may not be the best in the world but accidents can and do happen. Regardless which service you use.