This seems to be a good and cheap Ethernet adapter that works with the Switch. Realistically there should be no difference between a USB2.0 one (max 30MB/s) and the USB3.0 one (1Gbps ~~ 110MB/s) but I thought that in a tight spot it's always better to have a 1Gbps adapter handy.
Works right out of the box, not much packaging there. Switch detects it right away and, well, just works.
I'm a bit worried about multiple reviews saying this one fails after a while, but so far I haven't had a single issue with it