One Rythmik F12G in between Maggie MMGs. I recently added a small Miller & Kreisel K-9 in the corner opposite the Rythmik just to flesh out the sound throughout the room (it has one side open to the kitchen/dining room). Only adjustment was to the phase control - it now melds very nicely with the entire system and is literally two feet from my listening position. I get no localization from it.
So..............neither sub was hard to integrate.