Sorry guys. I completely screwed up in my last post. It was late here and I plead exhaustion. :-) It should have read: "these drivers have addressed many of the dispersion issues...the current iteration of the RAAL tweeters have significantly improved HORIZONTAL dispersion...VERTICAL dispersion still remains problematic". I have NO idea why I reversed it. Again, it had been a LONG day for me and I was very tired. When I logged on to the forum after work this afternoon and re-read my post, I had a genuine DOH! moment.
Also, to be fair, I have not heard the RAAL in the Ascend tower...I actually heard it in a Salk Verity. And the listening session was at an audio show. So it was admittedly not the best environment for critical listening. Nevertheless, I thought it sounded excellent. I think you guys may be taking my comments the wrong way. As I stated above, in my opinion ribbons offer some of the finest and smoothest high frequency performance available in modern speaker systems. I have loved ribbons for a very long time. I liked what I heard from VMPS many years ago, and those ribbon tweeters weren't even in the same league with the RAALs. In fact, I owned a pair of the original Carver Amazing Loudspeakers way back in the day, and as difficult as they were to drive, I loved the sound of those speakers. I think it's quite safe to say, I am a ribbon fan boy. :-)
So Dennis and Dave, I completely agree with your posts. And I'm sorry for the confusion my post caused. I still can't figure out why I reversed the words. Your measurements only confirm what my ears heard when I listened to the Salks.
And thanks for the info about the 70-10 and 70-20. I was under the impression that the 70-10 was the higher end driver based on power handling and SPL specs...specs which are not available for the 70-20...at least not that I have been able to find.