I use a myself, configure once at home and then you just plug in the power (microUSB, you bring the USB power adapter yourself) and the ethernet cord to the router and then connect on device. It's tiny (2.02*2.21*0.70 inches).

When properties have wired internet it's really nice as it's more secure (encrypted between device and router, no eavesdropping by other wireless radios - of course, without VPN hotel/internet provider can still see what you're doing) and the performance is usually way better than the wifi routers in the hall.

Unfortunately, while the hotels I stayed at more often in 2014/2015 had wired ethernet in the rooms, 2016/2017 was an off year. With everyone having wifi enabled devices a lot of newer properties (built 2010 onwards) don't put internet in the rooms, and older properties (early 2000s or older) tended to just add them in the halls, not rooms. The sweet spot is hotels constructed in mid-to-late 2000s, but even then I've stayed at many hotels where there's a wired ethernet plug in the room but it's no longer active (looking at you, Delta Toronto East).

It's still light/small enough where I pack it in my bag every time, just in case the hotel still has wired internet and it's still active.