I am not here that much, but I will try to help.
That's the exact laptop I have and no issues at all with my Win8 upgrade.
Asus does not have support the drivers on these for Windows 8 so I had to find them from the manufacturers.
Synaptic for the true Win8 integration (Side scrolling and side swiping)
http://www.synaptics.com/resources/driversRealTek for the latest Audio driver:
http://www.realtek.com.tw/downloads/Try maybe these drivers for the Wifi:
http://www.atheros.cz/atheros-wireless-download.php?chipset=37&system=7I can not vouch for the last link, I did not update the wifi.
Also make sure you have all your WIndows updates from MS. They may install compatible drivers that way for you.
Asus Z170X + Asus GeFroce GTX Turbo 1070 +... all kinds of Asus goodies. #Fanboi