I just replaced the M3v4 with the M5 in my 2000 ft^3 living room. The soundstage width doubled! The clarity is off the charts. And to my surprise, no sub is needed except maybe for bass management.

Andrew did an amazing job on that v4 tweeter. I swear that thing has a constant magnitude radiation pattern of 180 degrees. And the highs sound so much better on the M5 than the M3. Everything sounds better.

Once you hear the M5, there's no going back. I hope listeners aren't shoving this gift from the audio gods into cubby holes and cabinets.