I have had many packages from many sources shipped to my business, overnight priority, guaranteed by 10:30 am. I work for an auto shop, in a commercial district . We are only 3 miles from the FedEx hub which is at the airport where the packages fly into. Not once, EVER, has any package been given any priority over another as far as delivery time. Our FedEx guy delivers through our complex between 12:30 and 2:00 everyday. When confronted about this at one time, his answer was "We aren't going to make a special trip out here for 1 package." I then asked him why they guarantee it then and he said "That's not my department."
We also have several other gripes about their service but honestly its an endless battle that nobody will win. They get paid for a service on one end and the service is not provided on the other end. Nobody has accountability in the middle.