GaN-based Class D power amps

Mike Powell wanted me to correct my OP regarding the power output of the AGD Vivace monoblock amps. Unfortunately, I can’t edit the OP once someone responds.
While the AGD Vivace can output as much as 200W into a 4 ohm load, I interpret this to mean output power at clipping. The nominal power output is 100W into a 4 ohm load at the rated distortion specs. See the technical specs page from the AGD website:

https://photos.app.goo.gl/Suyt7GsGYmSXiv7JA

Regarding the cost of the Merrill amps in my OP, I incorrectly stated these prices as per monoblock chassis. I corrected this pricing error to reflect the price per monoblock chassis PAIR.

@erik_squires  If you take a look at OCD Guy HiFi videos on YouTube you will see Mike P's audio setup. I think if yo visualize his system you will understand.

Hi Guys and greetings from Germany!
I'm new here this is my first post in this forum. While surfing around through the internet looking for news about Class-D amps I found this thread and somehow had the feeling to add a comment. Because luckily I'm one of the 1st owners of a pair of the AGD Vivace GaNTiube monos here in Germany. When I finally got a pair of the "ready to release" version of the GanTubes I was blown away and could not stop to listen these little things. I must say I was used to a Nelson Pass F5 Turbo (pure Class A) and I always were happy with the F5 but the GaNTubes have blown it away. In every aspect, especially the mid-highs they distribute so much... lets say 3D sound. I was just astonished about the difference to my F5. It feels like you can grap
every single instrument or singer in the room. Just fantastic! If someone has the chance to listen to the AGDs I can only recommend to take the time and do so, it will be a great experience.
I'm driving a 8Ohm broadbandspeaker-Expo horn with 93dB efficiency. And it perfectly fits together.
Of cource 15k $ for pair of the AGDs is a lot of money but for HiFi lovers in my point of view worth every single Cent.
Cheers,Mallard

OCD has 4 AGD Vivace monoblocks driving his Maggies and subs via an external custom 4-way crossover. 

So nice to see a GaN thead with such a wide range of comments. I will add a few factual items here for the benefit of the readers and non circuit designers.
First of all Class D has been around since the late 1950's. The concept of Class D could not be fully realized until the semiconductor technology caught up with the Theory.

The theoretical assumption of Class D design is that the switching device – the transistor or tube, can switch instantaneously on and off. I will refer to the device as transistor from here on. If the transistor does not switch on and off instantly, a lot heat and current will be required. There is heat generated in the transistor as it goes from theoretical zero ohms to the off state of the transistor. This transistor acts a resistor which generates heat. The 2nd item is that the conduction will start between the positive voltage rail and the negative voltage rail as one transistor turns on and the other turns off. This causes more heat and more current to run, with potential damage to the transistors or very large amounts of heat and current flow. What Class D designs have done is to delay the turn on of 1 transistor until the other is completely off. At this point there is no processing while waiting for the transistor to settle down. This is called dead time. This is what folks call “Class D sound”. Which is quite true. One way to get rid of this was to use heavy feedback or feedforward to reduce this dead time effect. The side effect of heavy feedback (or feedforward) was sluggishness and loss of detail as the feedback loops tried to correct for this dead time.