So I went through with the YPAO process last night, and used "Natural" as the EQ settings. I figured natural would be the best because all I do is watch movies and play video games. It said one speaker was out of phrase, I double checked the wiring and it was not. No big deal. I immediately noticed a difference in sound, the quality didn't seem as clear as with direct input, but no big deal. The surround affect in video games was a lot better, I was impressed. And it seemed like it nailed the rear speaker levels perfectly, despite the unequal difference. The distances seemed correct, except for the sub woofer of course. Easy fix though.
All in all, impressed with the feature, I'm glad it was recommended to me! I'll save the DB meter for another day.