Power saving is a bit of a gimmick. I don't need any help with powering down etc. and the whole thing can be a bit of a nuisance. It is useful though, for the screen to go dark if you close the lid and come back by itself as soon as you open it again. The other need is for when you're on battery, totally absorbed in what you're doing, and the battery runs down. A gradual power down can help save the file you're working on before the computer stops dead...
**************************
Through difficulties to the cinema