With one driver we do not have any phase, timing and tonal discrepancy issues that plague multi-driver systems. There are no obscured bands in the midrange, hence there is a possibility to integrate the most sensitive midrange better to the room acoustics. When the integration to room acoustics is perfect, the jump is significant. With a well integrated multi-driver system the improvement is not as drastic, as the midrange is still plagued by issues from the multi-driver solution. The question is: do we want pure midrange (single driver) or extended extremes (multi driver)? Given that over 90% of our brain's sound processing power is in the midrange, we benefit most from improved midrange. We have a culture that obsesses with extremes, so most people go for that automatically. It's ultimately a personal choice. Just an observation: my friends who settled on a single driver solution have stuck to it, and rave about the music they are playing, and have no thought about speaker upgrades.... single driver sound has a rightness to it that multi driver cannot match. If you look for "submarine crashing to the iceberg" then they are not the right choice.