I think you’re right. When I A/B the two settings, with and without center, I immediately notice that voices eminate from the center. However, when I stop doing that and just watch something, I forget about it soon. Today I watch Iron Man and it was nice being able to understand dialogues without subtitles. I was looking at the action instead of the bottom of the screen, for a change.
I wonder if my search for a better center is pointless. I’m spending way too much time on this.