I haven't heard the NrT versions either, and I own RAAL Towers and Horizon center, but I can say that the RAAL tweeters are more clear and detailed than any other tweeter I've heard. Everything else has this sense of added distortion and bite, which can actually sound great to many people, as it appears to be more visceral, and some would even say more detailed as it may make some instruments sound like they have more body, even when they shouldn't. It really is a matter of preference in the end. I prefer to hear things exactly as they should sound, not artificially made to sound a different way. The main reason I went with Ascend in the first place is his goal of completely neutral speakers, and the RAAL tweeters were just another improvement in pursuit of that goal, with the engineering white papers to back it up.
Video: Benq HT2150ST Projector --> Silver Ticket 100" Fixed Screen
5.2 Audio: PS4/Nvidia Shield --> Emotiva XMC-1 --> Emotiva XPA-5 --> Ascend Acoustics Sierra Towers/Horizon Center with RAAL tweeters (L/C/R), HTM 200 SE (surrounds), Dual Rythmik F12 subs