Just own a Dell 15 7537 and it's very similar to yours, except some changes in DSDT. I use Clover UEFI and it works fine, have to patch DSDT for injecting HD4400 and disabling GT750 to save energy, along other usual patches. I tried to patch AppleHDA with no success, got Microphone and Headphone (with distorted sound), no speaker. That's why I'm still using your patched AppleHDA.
Very nice laptop, only some issues remaining:
- Sound does not work fully.
- Realtek 8168 does not work due to new chipset, have to wait for Mieze to release new version:
http://www.insanelymac.com/forum/topic/287161-new-driver-for-realtek-rtl8111/page-18#entry1982112
- Intel bluetooth works, Intel Wifi does not. Have to replace the card.
- Wake up from sleep results in black screen.
Btw, is the laptop easy to replace wifi card?
EDIT: Install GenericUSBXHCI.kext fixes the sleep problem.