OK, since this is a Wall Street Journal article from today's "Personal Journal" section, you won't be able to read it online unless you're a WSJ.com subscriber (my employer is). However, if mail is a big deal to you, consider picking up a copy of today's printed version, or taking the free trial to read this one. Some juicy quotes:

The latest post office statistics show that the typical Priority Mail shipment now takes more than half a day longer to reach its destination than first-class deliveries that cost as little as 34 cents. That compares to $3.50 for the cheapest Priority Mail shipment. And on June 30, the post office is set to raise prices for the delivery service by an average of 13.5%, depending on weight and distance. That comes on top of a double-digit increase last year.

The delivery performance lags in part because a greater portion of first-class mail is local, and thus delivered more quickly. But Priority Mail is also less reliable. One-third of Priority Mail items intended for delivery within three days didn't hit that target in the fiscal year ended Sept. 30, compared with a 19% miss rate for first-class mail. And it's getting worse. Priority Mail has slowed dramatically since last summer, with the average piece taking about 13 hours longer between drop-off and delivery. The average piece now takes 2.7 days to arrive, according to figures filed this month with the Postal Rate Commission.

[...] Jim Cochrane, the Postal Service's manager of package services, says service quality has rebounded in the past several weeks to its highest level in about two years, but he wouldn't disclose any delivery statistics.

Still, Mr. Cochrane concedes that it "might not make sense" to spend extra on Priority Mail for shipments going less than about 600 miles. That's because shorter-distance Priority Mail shipments often move only by truck, just like first-class mail.

[...] After next month's Priority Mail rate increase and a three-cent jump in the price of a 34-cent stamp, the potential savings from choosing first-class mail over Priority Mail will climb to $3.48 from the current $3.16.

Good stuff from the Journal's new Personal section, one Dow Jones has been heavily advertising.