Class D amps seem poised to take over. Then what?

Even the big high bias amps built with BJT's can't do it.

Oh dear🤦‍♂️, to say that an amp doubles, is just a "saying", maybe it should read "close to doubling", but hey, I didn't make up the saying.

No! amp can  perfectly double it wattage from 8  to 4 to 2 ohms, that would be a furphy, and would be like saying perpetual motion is a reality.

I can second the comments by those who have/have heard AGD amplifiers.
My bias towards Class D has been negative -my Bladelius Ask has a ‘green’ mode using a Class D module, which is flat and harsh compared to the ‘performance mode’ which is ClassA/AB and very good.
New speakers in another system are higher efficiency ( Viking Acoustics Berlin), and the LSA Statement (hybrid integrated) driving them sounds wonderful, yet is simply too noisy. I hear the tube hiss at lower volume and can’t ‘unhear’ it. My search for a replacement led me to the AGD Audion, which I had the pleasure to listen to at Ocean Way Audio in LA. I found everything stated about these amps, also in this thread and particularly by @atmasphere, confirmed. These are superb amps. Tube like sound and dead quiet. It does of course help when one of the most accomplished recording engineers in the industry endorses a product. In my mind, this is not a mere variation of a theme, it is a discrete innovation when you consider form factor and performance.
I ordered a pair…

Congratulation!

@rh67Thank you!

These companies that claim double wattage when impedence is halved don't give the actual 8ohm measurement, which is usually a lot higher wattage than their spec sheet has listed.

Our class D amps do 100 watts into 8 ohms and 200 into four. There is probably a slight difference due to the output impedance that causes the 200 watt reading to be inaccurate but its too low to resolve. But in reality the amp doesn't clip at 100 watts- it does so at 125 into 8 ohms but into 4 ohms it clips at 250 watts. So while your comment is true in some cases its not true in all cases.

You keep mentioning Wilson’s as being hard to drive, where does this come from?

For someone who "says" they’ve owned Wilsons, you are not very au fait or even interested in how they measure or behave, in particular the loading they present for amps to see.

While its true that the Wilsons have a low impedance in the bass (the Sophia and Sashas being the ones of their more recent lineup with which I'm most familiar) they really are reasonably efficient. When our MA-1 was hooked up to the Sashas (a friend of mine in town had them) the meters on the amp barely moved but there was plenty of volume. You have to take the drivability into account as well as the impedance. Our class D amps regard the Wilsons as a benign load.