@K-Moss You're right, it's an IPS panel. I just assumed the VA part in VA24EHE meant it's a VA panel.
The picture I posted before already had Vivid Pixel turned to 0 on the VA24EHE. Turning Vivid Pixel to 25 actually makes the text sharper, but in a very weird and unpleasant way (like applying a strong sharpen filter in Photoshop).
I checked the settings on the VX239, it turns out it had Vivid Pixel turned to 25 there already. I tried changing it to 0 and as I expected it made the font a bit blurrier but not as bad as VA24EHE.
There is a HUGE difference between how much Vivid Pixel affects the image on those monitors, on the VA24EHE it's insane and ruins the image, on VX239 it's subtle and improves the text.