I think it's very hard to determine if one speaker or another is more 'natural', as any one speaker can sound really good or really bad, or just really different, depending on the room and how they are set up.
For instance, I've heard my Monoliths sound everything from horrible to sublime, and that's in the same basic room that was custom designed to fit them. Why?
Well, room placement and treatment are the prime reasons, but there are others as well.
In the beginning, I had minimal room treatments, some foam absorption in key places to help tame the high-frequency resonances. But it was totally insufficient.
Moving the speakers around helped a bit, but fundamentally, there was a huge amount of high-frequency resonances, standing waves in the bass and huge mid-bass suckout due to the dipole nature of ESLs. At low volumes, it was ok, but as soon as it went over 87dB, the resonances would swamp the high-end and it was painful. Freq. response was all over the map. And timing resolution poor, as the passive crossover had no time correction for the panel to woofer integration.
Replacing the passive Xover with an active helped with a couple of things, mostly better frequency balance, and fewer panel resonances as I raised the crossover point from the way to low 120Hz point in the 250 to 350hz range and used stepper slopes. Still suffered from dipole cancelation, but less of it.
Room resonances were still impacting the rest, so several years were spent investigating and mitigating room-induced issues. See my threads on that from the mid-2000s.
Along with that, upgraded to a DSP-based speaker processor and was able to address the time-alignment to the woofer, and also replaced the woofer with a more suitable one. Mid-bass performance was improving, but still not great. Dipole cancelation was beginning to improve, but not really dealt with seriously until the
second wave of room treatments, when both low-end resonances and mid-bass energy from the rear of the panels was dealt with. That also mitigated many of the high-frequency resonances, as we now have a really well-treated room.
So now the Monoliths are starting to be able to play at reasonably loud levels without undue ringing and resonances. Peaks of 100dB+ are fine and sound 'natural' on instruments in very familiar with, like a grand piano.
But we still have a lack of mid-bass 'slam' on instruments like tympani (or rock bass and drums). There is a room-shape induced null at the MLP, so that's where the
MidBass modules help fill that in and deliver some tactile feedback as well.
So today, 18 years later, the same basic speaker in the same basic room sounds (and measures) completely different, thanks to the progressive sequence of acoustical and system changes that help it achieve the level of performance that gets it closer to 'natural'.
