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

I don't think there is an amp made that can direct drive the apogee full range, the midrange when direct driven is .14 ohms

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!