The beryllium tweeter on the DeCapo is well implemented, no brightness or harshness but they were a bit bright when I first heard them and when I got them home. It was my impression at the time that it was a break-in issue and this has turned out to be true. What is noteworthy is that these speakers will reveal issues with recordings that are closely miked and exacerbate that fact. Not that they are intrinsically bright but some instruments, like flute or even piano at certain frequencies can sound peaky on such recordings. But no brightness and praise NO harshness whatsoever. I agree with Rebbi, they are just wonderful communicators with zero fatigue factor which would indicate in itself that the tweeter is doing it's job.
Beryllium Tweeters
I've only heard Paradigms Beryllium Tweeters but I absolutely loved them! What other "affordable" (>$2k new or used) speakers use them and what are your experiences with Beryllium tweeters? What other Tweeters rival the extension, air and sweetness that I was hearing with my Paradigm Sig 2's? DeCappo? Usher? ...?