Why use a PLC when say your Xbox 360 has built in Wi-Fi?
Good question, let me explain my experience of using both systems. At first when I got my VPN router I was stoked to use the built in Wi-Fi connection via the Xbox. For a few days it was working great and wasn't getting much lag at all but many times it would drop or not connect properly. After 20min of trying to figure out the solution I decided to go back to using a PLC. I was amazed that Netflix was actually working better and was not getting the crappy quality I was seeing before. Normally they wouldn't stream some shows in HD but with the PLC all shows were now 100% in HD. The reason why I think this was happening was because with Wi-Fi you have more obstacles to overcome and the overall speed drops dramatically by the time it reaches my TV. With a PLC you have very little interference and the connection is pretty much right from the router.
If you are interested in getting a PLC there is must read website that has just about every maker available in Japan, here's a link to Kakaku.com. One tip I read was make sure you can get a refund in case it won't work in your home or apartment. In some instances PLC's will not function properly, it will depend on your home's wiring system. Also make sure to not plug your PLC into the power bar, always use a direct socket.
Finally here is a really good video I found that explains in more detail about how a PLC works and how easy installation can be.
A PLC maybe not be what you're looking for but I just wanted everyone to know that there is an option out there that does work great with a VPN, Xbox 360 and Netflix.