I have my iMac set to sleep display after 7min, sleep computer (hard disk included) after 15min.
Reason is because I leave my Mac on 24/7 but I don't want it to have hard drive spinning when not in use (avoid wear) and I don't want it to consume electricity for nothing.
My Mac is always one mouse shake away.
I never have to wait for it to boot, it doesn't wear when not in use and it doesn't consume power when not in use.
One thing great about Macs is that the sleep function works and it works well.
I, for the life of me, never use sleep on Windows PC's. It only works sometimes and Windows needs the reboots now and then anyway because it tends to get slow after a while of being booted. Please don't tell me I have spyware or viruses slowing down my computer... I have built PC's since windows 95 and I always keep my systems maintained, running lean and I don't install crap software. Edit: I don't install crap software, apart from Windows itself... 😉