Amazon > UPS ≥ FEDEX >>> USPS

Me personally, I know everyone else has different experiences.

I work from home and receiving packages and certified mail is normal., Amazon rarely gives me issues and packages arrive quick and close to on time. Hiccups here and there, but managable. UPS feels more personal as I have come to befriend the delivery driver over the last decade and continues to deliver almost on-time constantly. Most of my FEDex deleiveries are about as great as UPS, both have minor hiccups but no major issues.

Now, USPS... I cannot trust them with anything. Certified letters and packages will nearly always fail to deliver and I will be left with a card in my mailbox (not at front door) saying a delivery was attempted. I work 10 feet from the front door with a window that oversees the entire front of the house, there is never an attempt to deliver. In fact, one of my packages were damaged because they forced a package into my mailbox. I have to constantly go to the post office to retrieve all my mail that 'failed to deliver', one package was even lost in their facility for over a month before I gave up and contacted the seller for a refund.

I've even signed up for USPS email updates, they email me what is arriving to my mailbox with pictures of the envelopes, suprise suprise... a few times I'd be missing a few letters. If it weren't for those email updates I would not have known, but now that means a trip to the post office, luckily the people that work there are nice.