Read my post, I mentioned them there. In addition, see;
*When you power up, you are saving your hive money, (coin) *It increases voting for you *It will increase your curation rewards. *It helps you to have more ability to vote in the governance of hive block chain. *You will be known in this hive as one among the pillars of hive.
(You go get mouth for here).
And many more. So decide to always power up your hive.