I'm sure everyone's seen this already, but just in case not,
here's a link to Sanjay's article in this month's Advanced Aquarist reviewing the 400W DE lamps.
To be honest I haven't been following the buzz regarding these so a few things caught me by surprise a little bit, like, the non-standard lamp lengths (so the fixtures need to be adjustable) and just how much variation there was in the results between the different ballast types. Like, if you used a M135 ballast you'd be OK with an Icecap bulb (output results were not bad) but the M135 results on the Avalon bulbs fell far short compared to the SonAgro ("HQI") ballasts or the others.
But it was encouraging to see the results of the M135 on the Icecaps because the outputs were comparable but the power consumption was on the low end of the scale (comparable to the electronic ballasts and beat only by the Icecap ballast running on 50%).
So anyhow it looks neat.