Needed: Honest Advice on high-end amps- either mono or stereo

Very broadly speaking in the high end there are a couple of takes on sonic presentation. The first is fidelity to the music. Audio Research, Conrad Johnson, VAC, Sonus Faber. Their empirical rule is real music... a careful and complete rendition of reality with the details in proportion to the real thing. So, for instance if you sit in a symphony hall and first listen to the silence then the most quiet start of a violin... through a full crescendo... the gestalt is accurately presented. I tuned my ears partially through having 7th row center seats a the symphony for over ten years.. 

Alternatively lots of system are designed around sounding good. improving imaging and bass beyond what is real. So, details are often presented much more promenently than they are in real life. Kick drums too forceful. The imaging presented in Wilson / Magico, Bermeister, Rowland are often incredible... with a piccolo suspending in three dimensional space... but this is not real.. not like real music. Sounds incredible. I have been blown away by the ceiling to floor wall to wall (forward of front wall) 3D sound staging. Amazing, but it doesn’t sound like the real thing. the gestalt is wrong, proportions wrong. Often these system are not emotionally connective as well. They are intellectually interesting but lack the deep emotional  connection that good midrange bloom and great rhythm and pace will give. 

That is one of the dichotomies. Components and systems are on continuums.  

Not too long ago, I decided to upgrade my amp from my Michi S5. Ended up rebuilding my whole system-all for the better-but this is about amps. The Michi S5 is, i think, outstanding at its price point. I listened to lots of amps and auditioned some at more than twice the price of the S5, without significant gains to my ears.

I tried to sell myself on tubes, but this is where we all hear differently. I listened to ARC, CJ, and VAC pretty seriously, liked VAC the best, but that is just not for me. To my ears, these create a very pleasant sound, certainly something I could be happy with, but its not natural which is what I consider musical. Its like a cup of coffee with a bit too much sugar. A little sweet, a little soft but lots of folks love that sound. These are all wonderful products, but not optimum for me.

I ended up with a Burmester 218 and Burmester 808 mk5 pre. This combination produces a very natural sound, plenty of speed and well controlled bass-much more faithful to the music to my ears. Contrary to producing some sort of sonic explosion, I find the sound to be a faithful reproduction of the music delivered with control and appropriate speed-never soft, but never bright. If anything, the 808 pre imparts just a touch of warmth. I've spent a lot of time listening to Boulder. The Burmester sound is not the same as Boulder, conflating the two is inaccurate as I hear them. Which one is "better" is a matter of taste.

Coupled with the Zellaton Plural Evo speakers, I'm really happy with my system-best amps and best speakers I've had in my room-to my ears, maybe not yours.

To your question-is it waay better? Not sure how to measure that-I think with amps, once you get to a certain level the improvements are real, but incremental and nuanced. I'm certain I made a move up-again to my ears. I think speakers are a little different-transducers make a bigger difference in my opinion. The Zellatons, to my ears, are a very big step ahead of the Sonus Fabers I had, which are themselves really good speakers. The Zells are the best audio purchase I've made.

Fortunately, there is good gear to suit all tastes at all price points.

For great Sonics, it’s not just the amplification but rather the entire audio chain matters including a well sorted room.  For instance, @kerrybh  Zellaton Plural Evo speakers are highly transparent and can reveal the nuances of the very best amplification assuming the rest of the chain is also at a highly transparent level- unlike lesser speakers.

For the money (Let’s pretend you and I  can afford them- may of us can) are they transformative? Exceptional? WAYYY better than a lesser mortals out there? 

Typically, we’re not chasing a “transformative” Sonics but rather finding Sonics that “resonates” with us - draws us into the music.  A sound with a lot of WOW moments, touches the heart and soul deeply. It’s definitely worth it.  

I’ve heard the Michi amps and suspect those are hard to beat objectively.  Subjectively, anything is always possible.

Somewhat decent value.....not the best but better than many if not most comparable big, bulky amps.

I strongly considered buying but decided to cheap out and find a more cost effective and more importantly for me a less bulky solution.

The incremental value a $20,000 amp has over a $200 amp is $0 if you yourself can't hear it. 

Having said that, I'd suggest you listen to Luxman, a close sound cousin of D'Agostino even in the integrateds, Ayre and Pass as amps that can sound different enough to you to justify the spend. 

This is particularly important when selecting them to drive specific speakers as they will interact somewhat.