Out of the two ventures, only the USPS will send men with guns, legally able to kill you for competing with their business. Moreover, the only reason they handle so much mail is through that very same threat. Such monopolies necessarily stifle innovation and pursue the least efficient means possible to remain viable. The superlative of being the most beloved government institution seems like a tall midget contest and does not impress me or convince me of anything. Even if the trains run on time, I oppose the means.