The thing is, when you dig down into the USPS's fine print, their "express" delivery is not a "guaranteed" service. In other words, they will try to get it to you ASAP, but if it's a big mail day, or your carrier calls in sick, or you're on a route that doesn't have a consistent carrier, or or or... you're not going to get it when you think you are. But the trade off is that it's waaaay cheaper than UPS/FedEx overnight delivery. Regardless... still sucks.
The thing that just got me a bit ago was that FedEx, at some point, has changed their levels of service. There are now THREE "overnight" options. You've now got:
First Overnight - first thing in the AM, between 8am and 10am
Priority Overnight - first thing in the AM, before 10:30am
Standard Overnight - by 4:30pm at the latest
Didn't realize this until I was waiting for a "standard" overnight package, thinking I'd see it by 10:30am, like always.
Definitely will have to remember that UPS insurance trick.