The importance difference between us here is surely that whereas you say that Father, Son and Holy Spirit each have their own separate essence/nature, I would say that they all share the same one. In my system, the one essence/nature of God is fully and indivisibly present in each of them. In yours, there are three separate Godly essences/natures, one in each of them. Isn't that what makes your take polytheistic, and mine monotheistic?
I'm currently preparing a reply to your main response...
Bookmarks