That was kinda interesting... On my Hackintosh, traditionally, sleep never worked. When I am writing "sleep" here, I mean the sleep mode of the computer that puts the workstation into standby after a while of inactivity. Manual sleep, in like putting the computer into sleep manually, never has been an issue, neither has been waking the computer up again.
Carelessly, since I am not used to (automatic) sleep on my Hackintosh, I had a long job running over night, I thought. Getting into my study in the morning, I realized that my computer was actually not "ON". No big deal, maybe I switched it off, I thought in the morning confusion of my slowly awaking brain. But no, hitting the power button, the thing came to life, just to continue what I wanted it to do all night (only that it took all day now).
It seems that some of the updates of OS X 10.9 brought OS X even closer to the Hackintosh hardware I am using (GB Z77N-WiFi & i5-3570K).
At the end of the day, I hate that my over-night job did not run over night, however, I am pleased with the fact that the last missing function, auto-sleep that is, is now available to me.