The lack of extension beyond 20khz isn't/shouldn't be an issue since less than 1% of the adult population can even hear above 20khz (or actually: 1% can hear to 25khz). The fidelity laws are still set at 20hz-20khz as being one of the the ideals for speakers. Your concern would be just with how they perform in the same territory-below 20khz. That being said, its really how well the technology was done-there are good ribbons and bad ribbons (e.g. single-ended). I would go ahead an audition the piega's. There's not alot of musical information above 20khz either. Some stuff like cymbals contain harmonics as high as 100khz and studies have show that when exposed to stimulus' above 20,000hz there is/was brain activity, but no listeners subjective evaluation was able to detect the stimulus even though it was happening to them. I don't think it would be "a waste of time." Ribbons can be good. If you don't like them it would probably be for all sorts of other reasons, like distortion levels or something. Listen to the Piega's and some other stuff in the same price range to get a feel for what you like. And don't feel pressured by the dealer even though he is doing something nice. Its an expensive purchase and you want to be happy with what you get-trust your instincts on it.
