PROF - On speaker break-in... It's difficult to hear in 'real life', as your new spkrs. are going to break in gradually, over a long period of time. Like the frog in hot water, you may not notice the gradual improvement.
Most people notice it when they replay something they had listened to early after the spkrs. have had a month or two of use.
If you can audition duplicate spkrs. - broken in vs. brand-new - it's much easier to discern.
RE pricey cables... I didn't say they weren't too expensive. While some cables are much more expensive to produce than some people here understand, the mark-ups are also quite high. The question is not how the price relates to the costs, so much as how it relates to the resulting improvement in sonics.
In my case, I've found that cabling can make huge differences in sound - at least, they're huge to me because they get me closer to reality. In fact, I think of interconnects & A/C cords more as 'components' than 'accessories' due to their impact on sonics.
As always, not asking you to take my word for it, so much as honestly sharing what I've heard. I did not believe cables could make such profound differences until I'd heard it myself... repeatedly.
Example: My Sunfire amp has a dedicated A/C cord, because 20 yrs. ago Bob Carver did not believe it could make a difference. His new tubed amps have removable A/C cords, because since then he's HEARD that he was wrong.
I don't intend to change anyone's mind, but if I can OPEN one or two, they might change themselves...