I'll agree with what the others say about omnipolar speakers giving a big, enveloping sound, but lacking in imaging and accuracy. This would be especially noticeable when compared against the Axiom bookshelf and tower speakers, which are known for their very precise imaging. Then again some people like the sound of omnipolars; I know people who have mirage speakers and love them.
Even if you were going to use omnipolar speakers for your mains, I wouldn't recommend using the QS speakers because they have pretty limited bass extension, the -3db point is at 95hz, which is totally unacceptable for main speakers IMHO. Also, the driver configuration on the QS speakers woudln't be very good for mains; omnipolar mains usually have drivers firing foward and back, not up and down.
