I purchased these, and have since sent them back.
Here is the review I posted on a few review sites:
Review for everybody other than the family 'computer whiz'/Summary TL;DR review: Product is so poor you'll think it's faulty - but it's just bad design. Great marketing though! If you are lucky you'll get 10% of what this product claims to offer, our experience was less than 3% of claimed speed. Most of the time your facebook messages and lolcats will traffic jam faster than cars on a British motorway at rush hour.
I used to have respect for Belkin, their products are cheap but solid, but I no longer feel that way. We recently upgraded to the new Virgin Media 100mbits service which is quite simply impossibly fast. Over a gigabit ethernet cable we are easily capable of getting 11MB/s out of the connection, even at 'peak times'. Unfortunately, our (rental) house is quite large and we are unable to lay proper cabling. We had previously been running a combination of Wireless N and some 200mbit ZyXEL homeplug devices. From these devices we were able to get between 3-6MB/s download speeds from steam and other services. We saw these Belkin devices on offer at about £55 for two with a claimed speed of 1000mbits/1gbps - we figured 'hey, even if it runs at 10% of the speed its still good enough'. Well yeah... so much for that.
Our initial tests from upstairs to downstairs yielded between 2 and 3MB/s. Sure that sounds great, but both wireless and the homeplug devices we had previously could run at double that. We tried a few more tests at one point we managed to get a blistering 15MB/s between two machines in the same room. Wow! Not... 15MB/s is approximately 120mbits, or 12% of the total quoted speed - and that's in optimal conditions. A few hours later we tried again, this time getting 3MB/s between machines in the same room and then testing upstairs to downstairs yielded 200kbps. I could morse code the bits down the powerline faster than that. Latency is also severe with these devices. A ping from one machine on wifi to another on the ZyXEL homeplug takes 4ms, <1ms from wifi to wired. These Belkin devices are giving pings ranging from 17ms (best we saw) to 400ms (worst case), with average pings about 45ms. Pinging Google takes 26ms.
I contacted Belkin about the issue, their online support staff were helpful and friendly but first level support quickly gave up and deferred me to a higher tier support level. After a few days he emailed me back and confirmed my results and testing methods. After a few exchanges and a few attempted fixes the device was running at exactly the same speed and the tech confirmed to me that this was the maximum throughput I could receive. Wow.
The product has since been returned as 'not fit for purpose', and I urge you all to reconsider buying these devices. This is not a fault with the technology - the 3 years old 200mbit devices we have run at double the speed of these and without the insane pings.
There are a few reviews out there that suggest that a firmware upgrade may improve speeds - these speeds are WITH the firmware upgrade.
Just to confirm for any tech savvy readers, we do not have any surge protectors in use on any of the sockets where the devices are plugged in, and all PCs are very high end machines (i7/16gb ram/1g ethernet port etc).
Raw numbers:
Belkin:
Upstains -> Upstairs ==> 15MB/s
Downstairs -> Downstairs ==> 11MB/s
Upstairs -> Downstairs ==> 3MB/s (worst case of 200kbps)
Old homeplugs (ZyXEL 200mbit):
Upstairs -> Downstairs == 6MB/s
Wifi:
9MB/s (best case)
4.5MB/s (average)
