I know there is probably already a thread dedicated to this subject, but as I am new to the group and as such unworthy of employing the search feature you'll have to bear with me. I've recently pulled a vintage kit-built Hafler DH 200 out of storage. It's never been exposed to heat or moisture and still seems to sound as good as the day I finished building it (of course my ears have deteriorated in that time), but I know that with an update it would sound so much better. I've read plenty of reviews arguing for either the QUA-CO OR the Musical Concepts boards, but have yet to hear anything from someone who has actually heard both and can render a reasoned rather than an emotional opinion. Is that person out there???