I bought a pair of this 2 days ago, plugged them in, and the first experience was very good:
They instantly linked up with the blue light indicating a good connection between the two units, and I started attempting to stream some HD content across my home network and was pleased that the 720p stuff that wouldn't quite work before with my old 85Mbps rated Homeplugs, did now work.
However, from there, it was all very downhill.
The next day, the connection between the two rooms appeared to drop completely, which upon initial diagnosis appeared to be because the DHCP server (built-in to dsl router) in one room wasn't giving IP addresses to the computers in the other room. After initially suspecting the router's DHCP server was dodgy, and giving out static IPs, I was still having no end of problems are eventually traced the problem to the Powerline line adapters (why I didn't think it was this sooner I don't know - perhaps because I had so much Hope invested in these units and I really Wanted them to work - I really did).
They just randomly don't route packets between the two ends. They worked for a bit, and a bit faster than the rest of the products on the market but this gain in speed comes with a terrible sacrifice of reliability.
They might work well in some homes. For me, they are not fit for purpose. I'm sending mine back.
Some might say my expectations were too high, but my expectations are this;
If the wirings's good, it should run at High speeds
If the units can't maintain a high speed connection reliably, the speed should be reduced until reliability is achieved.