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

I like and have kept both. I’ve got a vintage Class A Pass Aleph3 (driven direct from a Wyred DAC2DSD) and ICE-based Wyred SX500 mono’s paired with a highly modified Rogue Metis (running Tung Sol VT99’s via adapters). The Aleph3 has an intimate continuity in image depth.. magical midrange while the Wyred’s (paired w my specific pre) have finesse and LF control while painting a detailed but natural cinematic stereo image. One is great for colder months and the other for summer and fall. I have tried the SX500’s driven direct from the DAC2DSD and thought it was nearly unlistenable, however. The right tube pre can have a way of ’sorting out’ older (but w well implemented output stage) class D topology into something that can still work now. The Rogue Metis Magnum is fairly dynamic (and a tube-roller’s dream/nightmare as an unbuffered tube design), but definitely a bit rough in stock form with stock tubes. I’ve got a good dozen other boxes in another room of other good-value separates; tube, Class D, and Class A, Class A/B, but these are the two setups I still use.. and I still go to shows. If I had money burning a hole in my pocket I’d like to try a Riviera Levante, Linnenberg or Kinki Mono’s.. a Nagra Classic amp.. perhaps some AGD Duets. I’d also like to try a Perla S50 integrated some day.. which I’ve heard with two way monitors before.

it’s more system synergy and implementation of the topology than topology, imho.

in my 40y + sound works I haven’t seen such speaker, with purely resistive load (2/4/6/8/12/16)! In order to design output filter properly, we need to take complex model of loading, including variety of speaker cables, DC protection relay ckt, speaker crossover, spkr driver/s complex, often resonating impedances, which is tremendous engineering task!

@westcoastaudiophile Actually its far simpler than that. A good class D amp can double power into a 4 Ohm load like any good class A or AB amp. There's no concern if the load isn't resistive! This is a no worries situation WRT the output filter.

In our case the amp is self oscillating, which means it also employs a lot of feedback. This prevents problems with capacitive or other odd loads causing resonance or the like- the amp is very well behaved with such loads as is any self-oscillating class D and so will be load invariant.

OP:  I have not really switched... I have A/B amp with tube pre-amp separates in one system and D integrated in another system. To my ears they both sound excellent with the A/B having a bit better control over the bass.

But it really stinks for me to buy them without hearing them.

This happens often in our hobby. 

Even with the 30 day return period. 

This seems like a very fortunate option vs being stuck with unsatisfactory expensive components