I really don't know where the appropriate place is to post this so I guess it'll go here.
I've been lucky enough to be present three times when a new component breaks in and goes from kind of underwhelming to
WOW! 
It happened two times on the upstairs system (an Ortofon 2M cartridge and then the 1.7 speakers). I could hear the speakers getting better but then all of a sudden they just totally opened up. It was funny how it did it as the soundstage got much taller over the course of about an hour right before they finished breaking in.
The cartridge was just dead as can be and I was thinking how I'll never have to worry about replacing it as it will never get worn out because it sounds so crappy so I'll seldom use the turntable when suddenly it just changed and it was back to vinyl for me.
That's the upstairs system and once those two things happened I've been happy with it.
I've always been unhappy with the downstairs system as I could just never get it to sound as good as the upstairs does.
I've always been really interested in preamps and feel that they're the heart of the system.
So there I sit, blaming the preamp for being such a blah and lifeless underachiever; the deHavilland does just about everything right except for dynamics. Flat, blah and lifeless, kind of like Jewel's hair, what's a mother to do? Nice soundstage, good overall tonal balance but I'm listening to some early Brian Eno, not Perry Como. Robert Fripp's guitar solo on "Baby's On Fire" should be ripping out of the speakers but it's not.
So there I sit, thinking that maybe it's time to go demo a few preamps and see what's out there nowadays when suddenly the sound of the album I'm playing changes dramatically. It's like somebody took the volume knob and cranked it up a few notches and the soundstage and yes, the dynamics, improve dramatically.
I was afraid to look as I've also heard that happen when a power tube goes Chernobyl but nope, no tubes having a melt down.
The Ortofon 2M cartridge finished breaking in while I was lucky enough to be sitting there listening and it did it in a real hurry.
The magic hit.
Has anyone else been lucky enough to be there when it happens like that?