There are few advantages to printing directly from PC rather than from SD. Most printers will display print progress and basic temp information, so unless you have a problem with a print and need more diagnostic information, then SD card is the way to go.

Most printers accept the commands over usb 1 line of code at a time - effectively in real time. Each command is then accepted and a confirmation of correct reception sent back to the PC. Printing from SD card is similar, with the data read sequentially.

I guess only if you want to remotely monitor your printer is there a tangible benefit to printing from PC. Personally, I use an IP security camera, but of course this would not allow me to remotely kill a print. I have a family to assist me with this