I think the argument for the ethernet dongle is that it's still a builtin ethernet controller, and all the dongle does it put the connector outside. It's just a

I think the argument for the ethernet dongle is that it's still a builtin ethernet controller, and all the dongle does it put the connector outside. It's just a bit of plastic and some wires. The advantage is that you can use any dongle and you'll always have the same MAC address. This is relevant in some DHCP setups. I'm not totally convinced by that, either, but at least the dongle is included in the box (X1C5).