"Vs" may not have been exactly your intent, but is handy when searching for information. It seems to have become the standard expression for internet comparisons.
I like both of these films, but neither has become a standard for me. I think the biggest difference is the characteristic curves. Delta 100 is a tabular grain film that seems to have more of a straight line response with more highlight contrast. Pan F Plus is a traditional emulsion and will shoulder off in the highlights. In some situations like the natural subject textures you mention, this might give somewhat more midtone contrast, depending on the scene of course.
I never entirely got the hang of Pan F Plus, probably due to the speed, but do tend to prefer a film with at least a bit of a shoulder. Others like a straight line response. The differences are there though to use as you prefer.