Wow', my post logged at exactly the same time G-man; I didn't mean to jump your thread. I think the sound gets better because the electrical forces re-form capacitors over time and equalise bias loops etc. Heat and power change compliance's and any materials must seat themselves to function to their best advantage; like an egine runs better after it has locked in.
But thats just my guess and it may be 100% wrong.
I know my oil-filled caps are finally opening up becuase my jaw dropped suddenly after two weeks of listening and I heard a whole new sound. Must be the heat loosening things up on the molecular level.Hey; did you order the Marchand Kits?