For something a lot cheaper...
It don't got no fancy USB, but the "power angel" by seasonic <http://www.seasonicusa.com/power_angel.htm> is great for this. I have my desktop plus two 21" lcd monitors plus desk lamps and electronics lab gear all plugged into it; very illuminating to see what takes how much power. The monitors together equal the whole computer; a large stereo also plugged in takes hardly anything even at loud volumes; and you can even clearly see how a computationally intensive screen saver burns 30W !
Recommended.
Jesse