This little adapter does just what it says on the box. It plugs into a USB socket and provides an ethernet connection. It brought one of my old PCs back to life when both the onboard ethernet connectors stopped working, so on that basis alone it gets a good score.
The main downside is that because it isn't an onboard LAN connector, any system set to wake up on LAN usage won't recognise it. I used to be able to wake up the PC from another room but not any more.