Oh goodness Brian!
I am guessing with all of the money problems the postal service is having that priority mail is being "hubbed" more.
That said, every month or two I mail my daughter living in Hawaii a care package from our very rural post office (open a whopping 2 hours on Saturday morning, town of about 1000). Almost always, my daughter receives that package the following Monday, occasionally Tuesday. Amazing, since she isn't even on one of the major Islands, but in Kauai. If I mail it from anywhere else, any other day of the week, it can take 5 days.
Even the military boxes almost always arrive about 7 days later, sometimes 3-5 days, occasionally 2 weeks. I think it has more to do with when a package is mailed, and the hubs it goes through, and the size of the package.
I love the US postal service and their boxes, too bad Congress has their hand in controlling things. The system can be made profitable if allowed to. I haven't had what I would consider major problems with their priority mail system, but I certainly understand your frustration ~Jan