When comparing speakers, it is very important to bear in mind the psycho-acoustic effects that can overwhelm any actual advantage the speaker might or might not have.
When I was selling hi-fi (oh so long ago) I realized that I could pretty much sell any speaker I wanted to by convincing the customer it was obviously better than whatever he'd come in to buy. The one he listens to first is better: the louder one is better: the one with the most obvious (but not wildly boomy) bass is better. Set up to exploit all three and the poor sap is toast.
If one of the speakers is the Quad ELS57, which has pretty much no bass, plays quietly and sounds quieter because of its low distortion, and comes after the Cerwin-Vega or JBL, it is pretty much dead meat. Only if you spend some time actually listening, make sure loudness levels are comparable, and play something that doesn't need bass, AND you sit in the right place and the speakers are far enough away from the back wall and are driven by an amp which can actually drive them without oscillating - then you realize that there is really no comparison. The Quads sound pretty much real, and the others, whatever they are, sound like speakers.
Nowadays, I'd recommend the Sanders Electrostats over the Quads. They go very loud, they use a transmission line for the bass so they actually have some (and it doesn't boom), they are very flat indeed, and they are easier to drive (although they do need a bi-amp system with real power to avoid clipping). They are also just as uncolored and transparent.