At the factory, frequency response is measured at very low volume level at a constant signal with the microphone placed in the optimum location. (+/- Xdb @ 1 watt, 1 meter). It shows nothing of the character of the speaker when things really get going.
I'd be kinda like buying a car based on measured sound levels with a mic positioned at center console position going 30 mph on a pefectly flat surface. Not much of an indicator of whether or not it has the potential to create a possible medical emergency for passengers over 70 when you stomp on the "gas", or try to impress seasoned auto-crossers during cornering, or test the effectiveness of shoulder harnesses when you lock up the brakes. Or, whether it just gets you from Point A to Point B as quietly and comfortably as possible.
You gotta listen to 'em.