Yeah sorry not claiming they all sound the same... The 340SE tweeter for example sounds more distinct to me than either the NrT and Fountek's NeoCD3.0, same for the original Sierra tweeter... But, going from NrT vs Fountek Ribbon, I heard more similarities than differences. I mean that's a good thing, as sound reproduction gets better all products should converse to the same direction. But that was a non level matched & go switch speakers kind of test... Only alternated between both a couple of times and what struck me was that although the two speakers sounded drastically different, the top end felt quite similar, the Ribbon didn't strike me as "having significantly more air" or "being more detailed" or whatever, unlike the mids/bass/soundstage/imaging/etc., the top end sounded quite similar... But that was with the Fountek NeoCD3.0, RAAL or other ribbons are another story... Maybe it was my ears, or the listening material... I was focusing on cymbals mostly...
Or, maybe because it was one of the few commonality between the two speakers sound I thought it was more similar than it actually was... But all I can say for sure is that based on that short demo, the two tweeters felt rather equivalent, none seemed superior/inferior... So going on that short demo, I wouldn't spend $ to 'improve' the NrT tweeter to that ribbon, if it's even an improvement, I know in theory they should sound quite different, but I didn't hear it, weird... To be frank, I was expecting more differences than I heard... Like I said, rest of the speaker sounded drastically different, top end, not so much! So maybe that somewhat skewed the tweeter comparison...
I think Dave made a thread asking for recommendations a while back to highlight the NrT tweeter, maybe I should try some material from that thread and see if I hear more differences...