Hi dermott5,
Even if your listening seats are not in the sweet spot, I'd still recommend you use three conventional forward-radiating speakers like the Axiom M2s or M22s with a VP100 or 150 center and QS8s as the surrounds. That way, you will still get some directional information from the left, center and right fronts, and the dialog will be anchored at the video screen, whereas using multi-directional speakers like the Mirage Omnisats or QS8s up front may just produce a big diffuse wash of undifferentiated sound, with dialog all over the place.
That said, I've never tried using QS8s as main speakers so maybe they'd work quite well. I generally do not approve of using omnidirectional speakers in the main channels of a 5.1-channel setup because you want imaging specificity at the front, with dialog firmly anchored at the video screen.
