I'm researching tweeters for a pair of main speakers I want to build for a 100 watt/channel system. I'd say it's primarily for home theater, but I also want good music quality. It seems that most of the high-end tweeters are using ferrofluid, but one that I'm seriously considering (Vifa XT25TG30-04)touts "the absence of ferrofluid" as a plus. Now I'm confused! What are the advantages or disadvantages of ferrofluid? How does it affect the sound quality? Does it present any special design considerations? Any comments, opinions or experience are welcome. Thanks.