Attached Link: http://www.enmeshed.com/shadermagic/archives/000219.html

*I'm sorry, but I didn't know there was a way to optimize a product for P5 yet have it still workable in P4/PP.*

It's easy. Separate MAT files; many merchants do this. For example Fatale's critter has P4, PP, and P5 MATs. There are also a few modeling idiosyncracies that you have to take into account, but you can make models that are P5-compatible without making them unworkable in P4.

I don't believe I've ever had a PP mat that didn't work in P5.

The bump maps never attach correctly. They're either loose, or connected to Gradient instead of bump. Check out the link; it explains "the trouble with Victoria 3" - or rather, with her MAT files.

Try the tips in the link. You may find that Firefly is worth the wait after all, once textures and nodes are applied correctly.

And to me, the hair textures look the same in both programs.

It depends on the hair. The new Wedge II hair looks awful in Firefly, at least "out of the box."