There is a significant improvement in power consumption for the RNG200N. It uses 19/17 watts. The 788 is not listed, but the 787 uses 31/25 watts. The old Motos use over 50 watts on or off.
The 550D uses 11/11 watts, versus about 35 watts for the old 6200.
Ratings at: http://www.energystar.gov/ia/product..._prod_list.pdf