Here's an interesting article on class D:https://www.soundandvision.com/content/bruno-putzeys-head-class-d
This stuff really comes down to personal preference. By no means have I heard every iteration of class D, but I've heard quite a few and to my ears, none are as sonically satisfying as a pure class A or tube amp. I also prefer class AB in most cases. I recently heard an implementation of the NCore module (mentioned in the article above) in a newer NAD integrated. It was better than some of what's out there, but to my ears, still suffered from some of the same old class D faults, most notably, a sort of digital-like glare. It's a bit like the difference between an LP on a high-end analog rig and a CD of the same recording. It's difficult to put into words, but when I listen to class D based setups, I have a hard time relaxing. I'm probably in a minority these days, so I wouldn't read too much into my opinions. This is simply my take on the Devialet after a fairly short audition. It was good in most respects but just didn't emulate the sound of other topologies to my ears.
I only heard this amp with some Magnepan 1.7is. In contrast to many reviews, I feel those speakers are overrated, so they may very well have been the bottle neck in the system. The Parsound Halo integrated was capable of 95% of the same sonic strengths. It gave up a tiny bit of resolution and separation in exchange for smoothness and warmth. I much preferred the sound of the Halo in that comparison, as I was able to relax and focus on the music rather than the gear. Based on all my subsequent auditions of various options, I think a more appropriate price for the Devialet would be $5 to $10k, that's assuming one likes its presentation.