I have the Extollo LANPlug 2000 and it has by far the best performance (rock solid pings of about 3ms in my house), but:

1. It works terribly if you use more than 2. There's just some bug in the L2 switching where it will get confused about the destination; broadcast packets get through, but some packets to specific hosts don't go through. Rebooting the adapter fixes it temporarily. I ended up moving one device to WiFi and as a pair it works reliably

2. The firmware it ships with is a bit limited, but they provided me with something more configurable when I contacted support about issue #1