From my experience, it depends on where you live, and what you are shipping.
I live more than a quarter-mile down a dirt road, so USPS will not deliver to my house, they delivered to a gang box at the pavement. But UPS and FedEx and Amazon will all deliver to my house.
USPS seems to be a little rougher on the packages. I have received packages from customers with the knife sticking out of the box
But USPS seems to be less money for smaller packages. And FedEx and UPS are less money for a bigger packages.
The signature thing really varies between drivers. Because I have seen them all sign my name for me and just leave the box.
But UPS seems to be the most strict about signatures in my area, they will very seldom leave the box if a signature is required.