Having been around OP's for over fifty years and now having been fellowshipping with many other Christians. I have observed an interesting phenomenon, that those who embrace the Word and declare Jesus Lord, I don't see any significance difference in the results in their lives.
Healing> no difference.
Changed lives, other than outward appearances> no difference.
Love of God> no difference
Love for the Word of God> maybe stronger among non OP's.
Love of each other> no difference.
So is the proclaimed "greater power" in the lives of OP's just believing their own press, or is there real difference? After fifty+ years I say the Word in folks lives makes the difference not the OP's doctrine.