I downloaded and opened the three DNG sample files in Photoshop CC 2017 ACR 9.8
The defaults when opened in ACR were:
P4P file - temp 5300 tint +3; X3 file - temp 5100 tint + 1; X5 file - Temp 4500, tint +5. All other sliders at 0.
To improve the images to my eye, taste and monitor I did quick start adjustments in ACR as follows
P4P File- exposure -1, contrast -20, shadows, +30, saturation -20
X3 File- exposure -0.75, contrast 0, shadows, +70, saturation -25
X5 File- exposure -1, contrast -10, shadows, +50, saturation -25
I am no expert but the photos all look fine to me.