breaking in audio components

sometimes you get lucky, and a dealer or direct manufacturer enable you to audition a component for a trial period, after which you may return it, or get a refund if you paid for it initially.

sometimes the trial period is 10 days, usually no more than a month.

you place the component in your stereo systems, listen to "test" recordings and try to evaluate its contribution to the sound of your stereo system.

there is the issue of break-in. a component may or not break-in during your trial period.

what criteria do you use to determine that a component has broken in ?

you might ask the dealer or manufacturer how long it takes to break in the component, or how many hours of signal transmission is necessary in order to fairly evaluate the component.

there is always the possibility that the component has not completely "settled" sonically, while in your possession.

there is the chance that if you buy the component, its sound may change after the trial period ends.

is it always a crap shoot when buying components, or has your experience taught you when to tell that any further changes in sound will be minor and not affect your overall sentiment toward the component ?