There are so many different shipping options to choose from, it??™s difficult to make apples to comparison without locking down some of the basic parameters.
In my experience, I have had Some Priority Mail Packages Delivered» within a Single Day and I have Seen Delivery Times as long as 1.5 weeks. While the latter tends to be an anomaly, overall the delivery speed is somewhat random.
FedEx» and UPS» however, always guarantee their delivery times but are significantly more expensive. In some cases, FedEx and UPS will cost you will over 2X the cost of USPS» .