Sleep is OOB for virtually all recent mainboards. In the earlier days it required DSDT patching, but that's not necessary any more.
Sleep/wake will break when using unsupported graphics though (e.g. most AMD or modern Intel iGPU with legacy connection). Any Nvidia GPU will be fine.
Many issues are caused by badly configured systems or wrong hardware selection, both of which can be avoided by reading (and understanding) a few simple guides.
I started my journey with a Nehalem based Hackintosh back in 2010. Choosing the correct hardware was very important back then, so I bought the same mainboard tonymacx86 himself was using, which guaranteed having pre-patched DSDT files for all BIOS versions. Getting my HD 5770 running required some extra treatment, because support wasn't native yet (I remember copying .kexts from a recently released iMac) and required IOReg injection.
None of this is an issue any more, installing El Capitan or Sierra on this machine is as simple as downloading Clover and using it to boot the installer. Post processing doesn't require more than choosing the correct audio codec and installing an Ethernet driver. tmx86's tools can further automate this process.
Installing minor OS updates hasn't been an issue in this decade, it has always been as simple as on a real Mac (as long as one stays away from hacked system files). Thanks to Clover major OS updates can be installed the same way, but it's a good idea to update Clover first in case Apple has made any low level modifications to the system (e.g. introduction of SIP).
I'm not claiming that installing a Hackintosh is as easy as unboxing a genuine Mac, but it's certainly not more difficult than maintaining my aging MacPro3,1 (installing Sierra & Updates, installing GPU upgrades, USB3, ...). My Nehalem Hackintosh will most likely be fine until Apple starts requiring a newer instruction set.