Tweeters

Earthquake are you leaning toward a specific speaker;if so
you might want to ask questions about that speaker or specific driver and the electronics you are using.
I think you will get better responses from people who have what you may be considering and this will give you more information to help you get what the speaker or driver can and cannot do

Hahnzie said a compression driver is [typically a piezo driver] this is not true. Compression drivers are not piezo electric. They are domes.

http://www.zaphaudio.com/tweetermishmash/

DIYer Zaph tested a bunch of tweets

That zaphaudio list is interesting. Zaph also did a test of ribbon type tweeters that concluded that they tested relatively poorly. A $29 vifa dome outperformed 4 out of 5 on paper. Cant remember what manufacturer I read recently using two domes to replicate the dispersion pattern without using ribbons.
I have speakers with ribbon type "isodynamic" hivi tweeters and I think the high end sounds very nice. Silk, fabric, metal domes, or ribbon tweeters, I think the crossover and overall design of a speaker has more to do with the sound.
My advise is pay less attention to the type of tweeter, and listen without bias. Your ears will find the speaker a talented designer has made for your tastes.

Zaph link is very miss leading. $29 vifa domes no where near the performance of any ribbon of quality. What zaph is testing for means nothing to sound quality or end result. If you look at Zaph they offer most all loudspeakers with ribbons.