I have to agree with Trelja on this one. Historically, metallic type tweeters have been prone to razor sharp detail,but also to a substantial amount of brightness. At first you say "I've uncovered a wealth of new detail", but then the reality that your not enjoying yourself as much sets in. Metal drivers seem to do it in every application I have heard. Some examples include, Dick Sequerra" ribbon tweeters, Apogee, ATC, Platinum and most Infinity designs. There are always exceptions, but brightness in tweeters is generally the worst offender in listener fatigue.
