Hi,
According to my understanding -
Pathfield - should be used to pick link target for href, wherever you don't need to browse/see resource preview
Pathbrowser - should be used to pick assets. It allows previewing resource.
it is recommended to use Granite(Coral3) resource type over coral2.
Coral2 - granite/ui/components/foundation/form/pathbrowser
Granite - granite/ui/components/coral/foundation/form/pathfield
Arun Patidar