Updated from AppStore without problems.
One thing though: No need for Nvidia driver? It is working with default macOS Graphic Driver in 5K Resolution.
However Night Shift doesn't work, I am still using flux.
Here's the System Report - Graphics/Display Section:
NVIDIA GeForce GTX 970:
Chipset Model: NVIDIA GeForce GTX 970
Type: GPU
Bus: PCIe
Slot: Slot-1
PCIe Lane Width: x8
VRAM (Dynamic, Max): 4095 MB
Vendor: NVIDIA (0x10de)
Device ID: 0x13c2
Revision ID: 0x00a1
ROM Revision: VBIOS 84.04.36.00.72
Metal: Supported, feature set macOS GPUFamily1 v3
Displays:
DELL UP2715K:
Resolution: 5120 x 2880 (5K/UHD+ - Ultra High Definition Plus)
UI Looks like: 2560 x 1440
Framebuffer Depth: 24-Bit Color (ARGB8888)
Display Serial Number: [[deleted]]
Main Display: Yes
Mirror: Off
Online: Yes
Automatically Adjust Brightness: No