Those are not really ribbon tweeters in the true sense of the word. They are Heil AMT type drivers. I have not been impressed with them. They tend to higher distortion and more pronounced sweet spot.
True Ribbon speakers are just that, like those from
RAAL. The inventor was Stan Kelly with his Decca/Kelly ribbon.
I personally think good dome tweeters are hard to beat. Their dispersion also narrow with frequency.
The best option is a three way with 3/4" dome crossed at 4 to 5K range with a 3/4" dome rather then 1". These have good dispersion to a much higher frequency. However due to the almost total lack of good midrange drivers, 3/4" domes are now an endangered species.