BTW, the Heil AMT's are back in production. :) If anyone wants to make their own speakers with them. I've read nothing but good things about them.
Again, I love _some_ AMT's. In my home they are what I love most. I've heard awful AMT's and I've read reviews of some not being well matched to other drivers. (Troel's on Munich High End show either 2016 or 2017).
They are NOT all alike. The motors matter. Compression, distortion and frequency response in an individual line of drivers, not to mention how they are integrated into the rest of the speaker matter a great deal.
The one thing that can be generally applied is they tend to be physically larger, and therefore offer narrower dispersion. As you may have read me say, this could be good, or it could be bad. Depends on your room and listening habits. For me they are ideal.
So, buy what you like, but I would never make broad general statements about any tweeter technology being superior to another. Same for dome's, rings and beryllium or diamond.
Best,
E