On the point of a ethernet jack, it is also worth noting that Wifi is SLOW compared to a hardwired connection. if you have a lot of Wifi devices taking up bandwidth on your network the hardwired connection will allow for a much better connection to your home network. From what I can see in the instruction manual it looks like the DCS Wifi device uses a b/g/n standard wireless adapter, which is actually pretty good with up to 300mbps data transfer. What you have to take into consideration id=s that if you have a weak signal, or any interference on the 2.4GHz frequency, that speed can drop dramatically as the wifi must keep sending the same data back and forth until it gets a clear message. Also worth noting that that speed depends on you having a higher end wireless router in the first place, capable of the higher speed. A lot of folk have only the b/g standard router which caps at 54mbps. When compared to the 1000mbps and (mostly) complete lack of interference of a wired connection, having the ethernet plug is a good call on MTH's part.
Short version of this, taken from page 8 of the manual; "The smart device typically connects to the router via Wi-Fi, so there is limited benefit to using this configuration. It may improve overall performance in an environment with unreliable Wi-Fi network signaling."
JGL
