FWIW, here are my observations based on A-B comparisons of the Paradigm Signature Beryllium dome, the Focal inverted dome, and the Salk SongTower Ribbon Tweeter:
I don't know if these specific tweeters are necessarily good representations of their kind, but, there is very little audible to distinguish them.
I did find that Focal's inverted dome Be tweeter had a bit better "fullness" in the extreme high frequency (as depicted in chimes), but the difference was extremely subtle.
Likely, there are better RT's than the SongTowers which could equal or better the Focal Be dome.
I cannot say how much to attribute to the driver and how much to the design of the speaker, but the RT as presented in the SongTower was more sensitive to "aiming" than the domes. If you are listening from a specific location, that gives you tighter control over tuning the sound (imaging vs soundstage), but accordingly has a narrower sweet spot.
When comparing the Aluminum dome of the Paradigm Studio series against the Signature series, I could detect audible distortion in the aluminum dome (in the highest frequencies). I never noticed this without another speaker to compare it to. If ribbon tweeters have higher levels of distortion than domes, I never heard it from the SongTowers. This experience would suggest that some ribbon tweeters have lower levels of distortion than some metal dome speakers.
That is my two cents!