It appears that with HomePlug AV, the HomePlug folks finally have a technology that has a shot at being able to deliver high definition content around a home. AV not only has the >20 Mbps throughput needed for lightly-compressed HD streams, but it maintains that throughput better than previous technologies, at least in my test environment. If HPAV can do this consistently across a wide range of operating environments, it could have a leg up on DS2's 200 Mbps technology, which lost more throughput in the same test locations.
Figure 12: Throughput with four HPAV streams
The other thing that might give HPAV an edge is shown in Figure 12. It shows the results of an IxChariot test with four simultaneous TCP streamstwo transmit and two receiveeach running at ~18 Mbps! While this is a bit shy of the 20 Mbps frequently mentioned as needed for HDTV streaming, it should be fine for streams coded with H.264 / MPEG-4. So under best-case conditions, HPAV might actually be able to support a couple of HD streams with some bandwidth left over for web browsing and emailat least in my home!
Note also that the top total throughput number of 74 Mbps is higher than the 58.5 Mbps shown in Figure 7, which had only one transmit / receive pair running. What thisplus the coexistence test resultstells me is that either the HPAV bandwidth allocation algorithms are purposely leaving bandwidth unused, or that there is more work to be done to make them more efficient.
Moving on, pricing actually isn't too bad, especially when you compare the cost of setting up a dual-band draft 11n wireless network (currently around $300 for the router and $130 per Cardbus card). Street pricing for the PLA-400 will be $80 - $85 when the product gets into stock by the end of this month (February 2007). This is only $20 more than the Zyxel HomePlug Turbo PL-100 and only $10 - $15 more than street pricing for Netgear's HomePlug Turbo XE104.
The bad news is that the "coexistence" of the HomePlug family of technologies appears to waste a lot of bandwidth. So while your existing HomePlug stuff won't stop working entirely if you add HomePlug AV to handle video streaming, there might not be enough bandwidth to let both work transparently to each other.
It took damned long enough, but HomePlug AV is finally here and looks like it can be a contender for bringing a high-bandwidth network connection to an outlet near you. If you don't need to tweak its out-of-the-box settings, Zyxel's PLA-400 is definitely worth a look.