I ran the ARO with my wife sitting beside me. She looked like she was in pain and afterwards said she could feel it vibrating in her spine.
She must have been in a peak as it didn't bother me.
I didn't push the limits yet, but we watched the last 2 episodes of Rome as well as the Spiderman 3 trailer and it was VERY impressive. Very tight, but with a visceral impact I've never felt before. I could feel bass that I never knew was there before.
I don't have much experience with different subs, but all I can say is that the difference between the f113 and my old DefTech is NOT subtle, a very big improvement indeed. And there's no way I'll ever need more bass in that 2000 cu.ft. room!