Have you ever wondered why on earth does the money next to my post doesn't convert into your wallet?
Here is the answer: Currently the payout is done after 24 hours. With the new Steem release it will be reduced to 12 hours. In case you get new votes on the post this payout time can be delay even little bit more. If you go over the payout sum on any post you can see how many is already payed out and when the next payout will be.
Normally the payout is around 50% in Steem-dollars and 50% in Steempower.
The Steem dollars you can use at once. Powering down your Steempower you can only do after having 10x Steempower then your initial Steempower. Powering down Steem power to liquid Steem that you can transfer to others is done over a 2 year period. This is to encourage to help in the long term success in steam.
Happy steeming!