I have a B&W ASW 850 15" sub integrated with N800's. I use the Velodyne SMS-1 EQ and Rives Audio professional test measuring kit to make sure I was able to integrate the sub properly. Above all, my ears were the final measuring stick in which to gauge the quality of the sub integration. I love bass to, but, one should not hear the presence of the sub when it is on and it should not be localized. It should add some dynamic swings to music that has very deep bass, otherwise, one should not hear it.
Don't get me wrong, when I want to feel the bass, and play Aerosmith loudly, Train Kept a Rolling, I increase the sub volume a lot, because I can and because, the bass in that song kicks ass when played at very loud levels. Most of the time, I am driving the speakers with little 140 watt per channel mono amps and the bass is sufficient.
So add me to the pro sub camp. In fact looking for another ASW 850, just to increase bass as you know, but, you already knew that.
Ciao,
Audioquest4life