See I have the opposite, I love UPS. I always know what time they will be here if i'm expecting a package. between 10:30am and 11am every time.
Now the USPS, I recently shipped a package out, it got ripped open and the contents lost. USPS in all of their wisdom taped up the box and stamped that it was damaged on it and sent it on it's way. Any neanderthal with half a brain could tell that the package they were handling was empty yet they sent it on it's way instead of contacting the parties involved.