Not trying to stoke the fire, I'm genuinely curious, but are there any machines that are currently available that are using .55 W/Ghash?
The ASICminer BE200 40nm chip is 0.35J/GHash at rated voltage. Though as usual people will over clock them straight away thinking more is better.
Speaking as someone who has their products in hand, no they dont. They get effective about 1.1-1.2w/gh.