The Comtrend PG-9172 G.hn Powerline Adapter is the first adapter I've seen that is G.hn-certified. The G.hn designation is a specification for existing-wire home networking, including power line, telephone line and coaxial cable. This means the adapter is certified to work well in a mixed environment. As a power line adapter, however, it's equivalent to the HomePlug AV2 standard and has a cap speed of up to 1Gbps.
The adapter is backward compatible with existing power line adapters. It supports a voltage of between 110V and 240V and has an idle power consumption of just 0.5W. It also has a built-in QoS feature that automatically prioritizes video streaming and VoIP over other type of traffic.
For security, the adapter features AES 128-bit encryption. To turn the security on, you just need to press and hold the configuration button, while the adapter is plugged in, for 3 seconds, on each of the adapters in the network. Note that the security feature is only necessary when you use the adapter in a multiple-unit building. If you live in a single home, there's no need for that since the adapter won't work cross power breakers. Also note that in my testing, once the the security feature is turned on, the PG-9172 stopped working with other power line adapters, but only with other PG-9172 units.
I've never seen any powerline adapters that lives up to the advertised speed and it was the same with the Comtrend PG-9172 G.hn which didn't deliver true Gigabit data rate. It was however still the fastest adapter I've seen.
In testing with two units, the PG-9172 registered the sustained real-world copy speed of more than 330Mbps (some 41MBps). This is about half of the average real-world speed of a Gigabit connection and about four times the speed of a traditional Ethernet (100Mbps) connection. It was even about 25Mbps faster than the once-fastest ZyXel PLA5206KIT.
In all, the Comtrend PG-9172 G.hn is clearly the fastest power line adapter I've seen and faster than most Wi-Fi connections, especially on the 2.4GHz band. On top of that, a power line connection is generally more reliable than a wireless connection with less latency. I used a pair of the the PG-9172s continuously for days and never had any problems with the connection.
A power line connection is basically an alternative using a network cable between a router and an Ethernet-ready device and a pair of the Comtrend PG-9172 G.hn adapter is an excellent example of how well this works. Pricing aside, the adapter will save you a lot of time and hassle from having to run the actual network cable itself.
That said, like I mentioned at the beginning, the cost is the main reason I can't recommend this adapter just yet. This is because thecurrently costs just $70 for a kit of two, effectively half the price, and has very similar performance. You can also get the or the which are also quite fast for much less. On top of that with the upcoming AV2 2000 adapter, such as the recently-available , the Comtrend's top spot on the performance chart will likely be short-lived.
To be fair, the ZyXel PLA5206KIT kit actually cost $160 when it first came out some seven months ago so my guess is that a few months from now, the Comtrend PG-9172 G.hn's price will be significantly less. If you can wait until then, there'll be no reason why you won't be happy with it.