My experience with the "break/burn In" is mostly yes it does make a difference. The Magnepan speakers took about 2-3 months before they came alive. I have a recently rebuilt before purchasing, Carver M500t amp that took quite a while to acquire that Class A musical kinda tubey sound. My 1 year old ART9 cartridge is still breaking in after about 350 hours of use and now sounds marvelous.