I have heard both in the same dealer room but with different electronics and source. I thought the Q5 was a little bit more transparent, lower in distortion, and tonally neutral. The S7 was very smooth sounding, a bit warmer and had great depth, but it was played with the Ssubs in the front of the room which helped. They are both superb speakers and the S7 has the new tweeter which is excellent. It would be a tough choice. I would wait until revisions are made to the Q line, though I fear these speakers will be extremely expensive. The Q is built to a higher standard, better cabinets and parts. The S7 actually vibrated quite a bit. The Q1,3,5,and 7 have all been extremely inert with almost zero detectible cabinet vibration.
