Never, ever, ever, ever, ever get First Class Mail, though. I had a Head-Fi'er mail me something via first class, and it took 8 business days to get to me, almost two weeks when all was said and done. Plus, we just had a lease for our apartment disppear in the mail that was sent via first class. I cannot possibly imagine what makes it so, so slow compared to Priority, which usually is about 2-3 days, and was four days only once.
UPS varies based on the seller, I've found. PartsExpress somehow manages to get two day shipping out of UPS ground (no joke), while some ebay sellers have shipped UPS only to have it take over a week (watching the tracking just makes it more painful, and I've had to call them before because it was stuck and they were like "oh, oops, that package was accidentally put on hold").
One thing's for sure about UPS, though, they beat their packages to hell. We just had a radiator come in the mail, well-packaged, literally BENT from who knows what. I never ask for electronics to be shipped via UPS.










It also says that the item is out for delivery at 12PM today. How long does it take to get the package delivered?!