The Mirage Omnipolar and Omnisats have uniform room-filling dispersion, but with a forward-firing bias that improves imaging. The listening area is the sweet spot in the sense that if you are at a live performance sitting to the left of the stage, you still hear all the instruments and voices from the perspective where you're sitting. The Omniguide-based Mirages do the same thing. The center position is especially sweet, but the soundstage doesn't collapse when you sit outside the speaker pair. You still hear it as a soundstage.
I have a pair of Omnisat satellites and a pair of floor-standing OMD-15's. I also installed a sat/sub Omnisat-based system at my neighbor's living room. I've found that the Mirage speakers with the Omniguide mid/tweeter module are very easy to place for musically satisfying placement, but also reward more careful placement for better soundstage and imaging.
You will get good results even if you have to place the speakers close to the wall behind them, but you get better imaging and soundstage depth if you can bring them out 2-3 feet from the wall. The tonal balance assumes the "average" room with a mix of hard and soft surfaces, but you can definitely fine-tune the dispersion and treble energy by adjusting the ratio and locations of hard and soft surfaces.
I've gotten good results from both rectangular rooms with std. ceilings and open architecture living spaces with vaulted ceilings. Like I said, they're pretty accommodating of your listening area.
