"The Ultra High-End Speaker."

High end SOUND not high end gear begins when any speakers at any price is well embed mechanically, electrically and acoustically ( and i dont spoke about mere room acoustic here ) ...

Ultra high end sound ask for very ultra costly gear for sure ...

There is a difference in cost between a minimal acoustical satisfaction threshold and the higher acoustical optimal threshold possible ...

My point is : it is acoustic science not the gear price tag who define the conditions for the winner ...

My point is two subjective/objective thresholds in the law of diminishing returns are DETERMINED more by acoustics knowledge in the design and in the subjective acoustic experience than by the mere price tag ... Sorry for some of those who own one million bucks system , it is not a warranty for owning a ULTRA high end sound because the gear component cost such and such, it is way not enough ...

Then i will not speak mostly as the OP about the ultra high end speakers choices because this is less meaningful than speaking about this specific system/room or this other specific system/room with or without the BACCH filters for example correcting any faulty stereo system nevermind his price ...

Psycho-acoustics rule the show not the speakers price choices linearly ordered ...

My two cents ...

I've gotten to a point in my life when I no longer care about "best" if I can't actually live with it in my living room space. 

For me, I go with large dynamic range, laid back, low distortion in small packages. I know the dynamic range plus laid back seems like a weird combination. For commercial brands I like Monitor Audio a great deal, with some appreciation for the modern Wilsons, and Magicos. With the right amps I might see myself enjoying some Klipsch Heresy’s as well.

It’s hard to separate the room from the speakers though. The best high commercial speakers I could fit in my living room may be far smaller than the most expensive. As such there’s a lot of very large speakers I would not realistically consider. Perhaps the largest commercial speaker I’d consider in my home is the Arion Apollo. Always had a soft spot in my heart for line sources and AMT drivers.

For me no speaker is ultra- high-end unless it's a headphone. There you have a lot more possibilities to get as close as possible to the raw natural sound.

If you cannot perceive that the so-called "high end" speakers are better than yours, then you have probably crushed the competition.

My system is much less than yours. I think it sounds wonderful, even compared to more expensive systems. Often, they do things that my system cannot do -- bass and dynamic punch, super accurate sound staging. I've got my system doing something better, in some cases, than those systems -- intimacy in midrange, naturalness of soundstage, precision without hyper-articulation in instruments and highs.

I have heard a couple systems that do everything mine does plus the things it doesn't do. But they're not ultra-high-end. They are thoughtfully selected, matched, and placed in an intelligently treated room.

The soundfield of speakers and headphone are two different things ...

The timbre definition the immersiveness and all the spatial characteristics of sound which are numerous cannot be determined by the mere speakers choice...

Speakers exist only in a room, controlled one or uncontrolled ...

And any stereo system or speakers is impeding the spatial characteristic of sound by crosstalk ...

But headphone lack the body sensation of speakers and deep bass and they sound always artificial timbre ( my 9 headphones in particular) except for some very rare and costlier one ...The soundfield in most case STAY in the head ... ( save my K340 modified and perhaps top few others i dont know personally as the Raal or top Hifiman and Top Omega Stax )

Anyway timbre, immersiveness and spatial characteristics of sound dont come with speakers price tag ... They come with room acoustic coupling and with adding to that the necessary BACCH filters which is the acoustic last revolution ...

Nevermind the price you pay for your speakers ...Or even for your headphones... You will need acoustic material control and/or acoustic DSP ...With my K340 i need the two as with my speakers ...

My low cost system now is satisfying so much, but why ?

Because i succeeded creating a room/speakers relation very intimate as with headphone in a near listening position in a controlled small room ... And i succeeded in creating with headphone a soundfield speaker- like in timbre and spatial characteristics out of the head in many recording ... For me it was the goal... I listen music alone ...

Ok i spoke too much and we will go to the "Bugatti" and " Veyron" level speakers talk forgetting this new more affordable car that which is also a plane thanks to the BACCH filters .... 😁

Price tag  dont afford S. Q. ...Psycho-acoustics does at lower price nowadays ...