Higher sensitivity - more dynamic sound?

dynamic sound is a benefit, yes

but there are negatives too

complex set of tradeoffs in speaker design, many many variables

More dynamics if the speaker is of proper size better transient response less thermal compression in a home environment the ability to use almost any amplifier type made. Can sound better at low and high SPL levels.

MBL is a perfect example of not the most efficient ,But the low sensitivity is misleading ,for it disperses in 360 degrees sound evenly ,not just to the front 

and the tweeter,midrange  not being n a box and direct coupled have exceptional 

transient response, micro,and macro dynamics as well as dynamics ,

at a cost in  power required, and $$ cost. That’s why. Am forced to save to buy their excellent 126 model used with dual SVS 4000 SB subs. 

Uhm, never heard that one before, but ok....

Think of it this way, it is a combination of the loudspeaker and the amplifier that creates the dynamic range:

102dB/Wm sensitive speakers unpackage 102 dB range from 1W source material.

From the same 1W source material 82dB/Wm speakers unpackage only 82dB.

No matter how many watts we throw at it, the more sensitive is always giving us a wider dynamic range.

Now, if you need 102dB level with the 82dB/Wm speakers, then you need to bloat the 1W source to 100W, creating x100 distortion along the way compared to the 1W. To get the 100W reasonably error-free, to reduce the errors made by the additional amplification, we need feedback that removes not only the errors but substantially compromises the low level details as well, leading to a collapse of the low level of the dynamic range.