powersx2,
Welcome to the forums!
No coating is "better" for self defense. In such situations, some folks like coated blades because they hide the glare, making a knife a lottle harder to see. Some coatings are better at keeping a blade rust free that others, so there your question make more sense.
Like Quiet Storm, I much prefer a satin blade over a coated blade. I think uncoated blades look way better and I'm not too interested in subdued blades. Now, a black pocket clip on a folder is a good idea I think! My silver clips get noticed, while my black clips have been noticed twice.
Unless you live in a corrosion-prevalent environment, or you are in the military where glare off of shiny steel can be noticed by gun-toting bad guys, or you really like th elook of a blackened blade, choose an uncoated blade. If you do choose a coated blade, expect the coating to wear and scratch.