… a subject of great dispute …
I don't think it is in great dispute that some speakers are more dynamic than others and certainly having enough amplifier power can be an intrinsic issue in this.
Some folks are more attracted to a dynamic sound than others. Some prefer it so much that it is even priority 1, while others 180 degrees away, actually don't like dynamic sound - preferring a more subdued and mellow approach. It is not priority 1 for me but it is a high one. When a good sounding speaker has good dynamic qualities, that is usually where my toes start tapping and I can't help but love a speakers sound.
Unfortunately, none of the tests were get presented with can measure it well, though you can sometimes make a pretty good guess.
General dynamics and "dynamic attack", are a way of conveying in words the effect of the speakers being able to shock you with clean, clear, effortless SPL increases in louder passages/peaks in the source material - To energize the room. Micro dynamics is dealing with such things as plucking a string or the tapping of sticks - or in a film shutting a car door.
In terms of general dynamics you could likely place a microphone your room, set two speakers to have the same average volume. Then record them playing back a track that has a wide dynamic presentation. Then examine the resulting spectrum/SPL. That might be close to telling.
For myself it often boils down to difference between a good sounding speaker and one that starts to actually sound real, like a live show.
Unfortunately there is still some debate about in what way dynamics is real, which seems strange after having listened to countless speakers over the years. Not sure why. An easy test would be to listen to a track on a typical 3" full range mini speaker and then on a high end 12"/4"1" horn loaded 3way something or other. If someone doesn't hear a dynamic difference then great. Save that $ and space.
There are many variables in this.
In a lot of cases it boils down to size and available power/power handling/efficiency and desired average playback levels.
With speakers of similar size and driver configuration it can come down to robustness of the drive units. If a tweeter can handle more SPL at high volumes and IMD is low vs one that is compressing, or a woofer that is compressing peaks vs one that still has power handling and xmax to give.
There may be Doppler effects and IMD in a 6" with high excursions vs a 15" producing the same bass SPL yet moving 1mm.
Dispersion can be a factor, do you like when the room is filled with diffuse energy or do you like a smaller more compact stage. I personally find the wide staging often sounds more dynamic if only due to the greater sense of scale, of largess - even at similar SPL.
Bass depth is a factor, having more down below can deff give more weight to what is above, more scale and impact lead to a sense of more dynamics throughout the audible range.
So some of this can be measured and some is just going to be based on personal preferences and interpretations.
In great speakers these may be only a couple or a few DB differences in output on peaks and such but in terms of being noticeable IMHO they are.
I was actually surprised at how dynamic I perceived the Revel M126be to be vs the KEF R3. It is visually much smaller and a 2way vs 3. It was a noticeable amount for me( yet both speakers had their own versions of very good sound as both can play very very loudly for their diminutive sizes.)
If the Reference 1 is an even more neutral and robust R3 and also with better dynamics, then that would be a very good thing.
Pair it with a couple channels of 250-500watt power and never look back.
Anyway, I am surely way over my allotment of tangents.