I heard both speakers but in different systems with different room acoustics and different upstream components. I remember thinking the M5s were more listenable -- smoother with more body while the Q3 speakers were faster, more detailed, but one or two clicks toward center of gravity in the upper registers. Disclosure, I own S5 speakers (could not be happier with them...wonderful on every dimension that is important to me). I had one interaction with A Wolf at Magico and he was very responsive and friendly. I admire a man who can create something so wonderful... nothing but compliments from here. And people who work for Magico (e.g., Irv Gross) are exceptional and consumer + music focused.