I, too, have NEVER had a problem shipping USPS. Ever - but I have heard horror stories from others about ALL shippers. With respect to cost, though, it varies. I almost always find USPS Priority Mail cheaper - except when comparing to UPS or FedEx Ground. Where I live, Bay Area (CA), I will not have anything shipped to me via UPS unless I absolutely cannot avoid doing so. 2 of 5 times they misdeliver or just bang the living snot out of the package. I've declined to order a few times from businesses that say UPS only because of this.
USPS shipping prices ?
Went to the Post Office to ship a set of 4 pound cables with $200 insurance plus tracking to California via priority mail. Clerk tells me the cost is $14 and change. When I balked at the price, the clerk told me that it depends on the zone it goes to. I said, sounds like you guys are getting more expensive than Ups and Fedex. Went to Fedex and shipped the same package with tracking and insurance for $7.05. It used to be cheaper to ship via USPS. Unfortunately, this is no longer seems to be the case.