Summary: I wanted to put a security camera above my kitchen cabnets, where I had power but no easy way to run a network cable. I refuse to use WiFi for 24/7 streaming video so this was the obvious alternative. The adapters connected effortlessly from opposite ends of the house, on different breakers even, though only at about 40 Mbps. Still, it was more than enough speed for the purpose and it has been completely stable for months.
Summary: These things work surprisingly well! I would have expected as much using them in a house with modern wiring but this house is almost 100 years old, and so is a lot of the wiring. But this does not seem to phase these. I currently have 5 of them in place on 2 different networks both on the same electrical circuit. And with encrypting, the network segregation is working fine. Set up was fairly straight forward on the first network, basically plug and play.
Summary: My application required that the two units be a replacement for a cable. While I measured a considerable drop in performance, it was still quite adequate and eliminated a long cable that was, in this case, in the way. I'd say it was a good buy, and a good choice. Installation could not have gone more smoothly.
Summary: These work great, however the extra socket version takes up more space than the four-port version and it doesn't fit where I need it. I have an outlet built into a shelving unit near our home theater PC and, unfortunately, the outlet is close to the shelf. It's designed to plug into the lower of two sockets so you retain access to both. This won't even fit in the top socket due to it's length.