I guess it's just my own rig then, but break in of AC components hasn't really been very much of an issue here; most upgrade cords that I've used haven't changed very noticably when broken in, excepting the Virtual Dynamics Signature, which although already cryo'd did improve considerably over the first couple of weeks use.
This Wattagate 381 outlet has only been in use for 2 weeks now, and although it sounds fantastic from day one, it has either improved somewhat more over time or maybe it's me still getting accustomed to the overall sonic improvements. Over the past weekend I sat spellbound & glued to the sofa with remote controls in hand, not being able to stop myself from listening over several hours duration. This hasn't happened in over 4 years, so I know I'm finally getting closer to nirvana. If this gets any better over time I'll be all the happier still. It's as if this outlet has enhanced the effects of all the other tweaks already in place; it's finally all come together.
FYI: I use the Wattagate 381 outlet terminating a single 10awg solid copper spiral twisted dedicated line; at the source is a vintage household fusebox with a ceramic 30A edison base fuse.