Now you're going to cause me to have to dig around and find my KillOWatt meter and stuff.
I'd also point out the third perspective of only sleeping the display, to avoid the repetitive cooldown-warmup of either sleep or shutdown that ages electronics.
Also from your provided link,
The surge of power when a computer is turned off lasts a few seconds and is insignificant compared to the sustained energy used in keeping it on during periods of inactivity. They're not comparing it with sleep, but with leaving it awake.
