Has anyone switched from Class AB/A to Class D? Was it better? Was it worse?

I loved my Panny SA XR 50 in my bedroom system until it died.

@freediver  that's great feedback ... thank you!

I've had class A/B amps from Denon, PS Audio, Vincent, and Krell.

Very happy with my class D PS Audio M1200 monoblocks.

@tomcarr ya, I was eyeing the Class D PS audio monoblocks. But it really stinks for me to buy them without hearing them. Even with the 30 day return period. Were able to hear them first before buying them? 

There are a few differences:

1. I don't think we really know how long class D amps will last, how they will most likely fail, or whether they can be maintained in the same sense as a conventional amp.  They could last longer.

2. Class D amps use far more complex designs.  Many of the amplifier boards are built as modules and used by multiple amp makers.  That's why a class D amp will often be identified as a Nilai, NCORE, Purifi, PASCAL, etc.  Some (all?) of these companies also build and sell compatible power supply boards.  Add a case, power switch, input buffer. wires & connectors, and you're done!  I don't think all class D amps are built this way, though.

3. The more recent introduction of GAN FETs has made for another family of class D amps.  I don't know if these are also mostly being based on modular sub-assemblies; what makes them distinct is the use of a specific kind of transistor.

None of these are necessarily negatives, just things that occurred to me recently.  Hopefully, @atmasphere will drop by and fill in the blanks (please?)