I cringe when I see such definitive statements like this. How do you know this? Have you heard every other ribbon or even a comparison of the two tweeters in question? That is, each in a properly constructed cabinet for the particular tweeter? Also, the speaker being discussed has a midrange that goes up to 15kHz supposedly. How does that affect the response of the ribbon tweeter? That is, does the ribbon need to be great if the mid is so great?
I don't think you can tell much about these speakers without a direct comparison where the two speakers are in the same room and amplified using the exact same equipment, interconnects, etc. (and you consider differences in efficiency). Pretty much anything else is complete speculation.
I haven't heard either one of them and neither have you, I'm guessing.
The RAAL tweeter is the flattest measuring, lowest distortion ribbon (within its frequency range) that exists. Rick Craig has, and I'm sure Dennis Murphy has as well, measured pretty much every ribbon or planar tweeter around, and this one's the best. And one of the most expensive.
I never said one speaker was better than the other.