W/out restating the reasons why (but, I will anyway, lol)... sleep, sure but, leave them on not, fully Powered OFF.
1. It's better for or on electronics, can increase longivity. It's hard on them being shut on & off. Uses less energy letting them idle than turning on & off.
2. The amount of current they draw whilst idling or sleeping is almost immeasurable.
3. Powered off 'Automatic' functions don't/can't happen.
My original background is recording studios & broadcast locations (many other electronics based environments are the same) gains, on amps & so on, get turned down all the way but, power is left on, unless & except, if & when periodic maitenance is being performed.
Drew