If you can get your hands on a Z370, I think it's a better choice for hackintoshing.
Yes, Z390 is newer, but what new features does it give you? Nothing. Only two things separate Z390 from Z370, (1) Intel CNVI Wi-Fi and (2) Intel USB 3.1 gen 2. Neither of these two features are "new", just different and with questionable compatibility with macOS.
- Generally, Z390 motherboards have better VRM than Z370. However, that's not to say that you can't overclock with Z370. I overclock my i9-9900K to four cores 5.1GHz/four cores 5.0GHz on Z370 with air cooling.
- Z390 gives you the new Intel CNVI Wi-Fi, but you can't use it with macOS anyway. Whether or not you can replace the CNVI Wi-Fi card with a card that will work with macOS is also questionable. A few have successfully done it, but most have failed. The M.2 slots used on Z370 motherboards for Wi-Fi can be used with Apple branded Wi-Fi/Bluetooth cards for plug-n-play compatibility.
- Z390 includes Intel USB 3.1 gen 2 but I have yet to see any confirmation on whether or not they actually work at USB 3.1 gen 2 speeds in macOS. On Z370, USB 3.1 gen 2 is provided by ASMedia chipsets that have native macOS support. I've personally tested this on my Z370 motherboard and it works perfectly.
- Also, since the USB 3.1 gen 2 ports on Z390 are on the same controller as the USB 2 and USB 3.1 gen 1 ports, users will have considerably less ports than Z370 once the proper USB 15 port limit issue is addressed.
- As of today, native NVRAM is not working with Z390. Native NVRAM works perfectly on Z370. In my opinion, native NVRAM is a big deal because without it, you lose kernel panic reports on reboot. This can be invaluable for troubleshooting.