Mapping node and textures - Landscape project.

• I have been messing the micropolygon displacement. Making landscapes and the like. I have some 3k textures from poliigon. From the image texture CTRL-T for a mapping node and texture coordinate nodes.

• Im using the UV output on the tex-coords, and the texture option.

Image texture order

Color map

Gloss map - Roughness (I believe)

Normal map

Displacement map

Only maps not used was Reflectivity and AO

My problem is the one texture looks good

Ground 2K - set to 0.001 XYZ

But the other looks pixelated

Snow 3K - set to 0.01 XYZ

Also having all the maps for each image texture output from the same mapping node. Should I have a separate one for each? Would using Generated or Object be a better option, since Im dealing with a UV unwrapped single plane with no subdivisions?  

This is the complete image.