Which Tweeter preferred- dome natural material, Beryllium/Metal or Planar Ribbon? Why?

The best I've ever heard were plasma at the CES show 40 years ago.  They were that memorable.  

The AMT tweeter with a SET amp are pretty magical

@asvjerry 

Apollo Speakers

https://www.audiogon.com/listings/lisa0ffi-the-apollo-system-high-sensitivity-ob-line-source-amt-based-system-the-apollo-full-range

I would love to hear them.  

@asvjerry 

Sounds doable but Heil only go down to 800Hrz  the Apollo go down to 125Hrz to cover most of the vocal range.  They custom built them which why I suspect the price. 

As soon as my baffles get built (waiting on my cousin but the labor is cheap... beer mostly)  I'm planning a OB two way using the big Heil and a 15 inch woofer. 

I'd bet Apollo has an open house that you could listen too without the rent a blonde but then  again you don't get to rent a blonde.

You wouldn’t happen to have a pair in the Northwest would ya. I wouldn’t have to rent a blonde I married one.

@arion 

The ESS AMT will shine when played using a high current solid state amp, but they don't do nearly as well on tubes.

That's not my experience.  I heard them on a 12 watt SET amp and they were fantastic.  So much so that I purchased a pair of ESS and plan on using them on my DIY speakers.  

The time I heard them on a SS state amp they weren't nearly as impressive.  I'll admit completely different venue, music and presentation.