They do seem to be a niche market product, but for what reason I can't honestly say. Of all the different tweeters types I've heard the ribbon sounds the best to my ears. It's crisp without being bright, powerful yet not sharp. I really like the detail they provide. Ironically, I'm listening to speakers with a ribbon tweeter as I type this. They're the XTZ 95.x series, which will be my next review. It's been years since I heard a ribbon, yet I'm still amazed by them every time I do.