@schwartz36
I made my own speakers with Mundorf drivers, and the only other commercial AMT drivers I’ve heard were Golden Ear. The difference in quality was gross.
As for what I would want you to listen to so you could get a better idea:
ESS has the original AMT driver designs and are producing new speakers based on them. As far as I’ve read, they sound as good if not better than the originals, which never had the kinds of issues the cheapies had.
I’d also be curious to listen to Legacy, Martin Logans.
Perhaps the most ambitious speakers I know of with AMTs are from Gryphon. They use the same model of Tweer I do in a couple of their designs, but at $20K and up !!
I can tell you that measurement-wise, the Mundorfs are superb transducers, not only with a smooth frequency response, but fantastic time domain behavior, very low distortion, and incredible dynamic range and power handling. Those are all characteristics which describe a world class tweeter. I’d put them up against the best Be or Diamond drivers anywhere.
Best,
E