Cables (power, IC, speaker), along with clean power, and vibration control, are the foundation upon which a good stereo is built. Without a good foundation, no gear will perform at its optimum. However, with a good foundation then any gear you currently have, and any new gear, will operate at its best.
Ok, about a good universal remote control (rechargeable with base) that goes through walls behind you? ...That's important in a good home theater room system.
About wireless transmission? ...About battery operated components? ...No more worries about electrical pollution. ...No more worries about power purifier boxes.
Listening preference, accurate distortion, concrete measurements...sensory pleasure of the hearing...pure and simple?
Yep, personal preference in each system...no two are equal, same as us.
A $1,000 receiver comes with its own removable AC cord (a fairly good size one); the audio reviewer substituted it for another that costs fifty bucks...he heard better bass definition.
Then he tried a third one, $100, and he heard more details in the mids and highs, less reserved sound than the one that comes with the receiver, and the lows are deeper, more extended, more reverberation, more euphony...the audio reviewer recommends the other AC cords, they sound better.
I have the review right here, and there are hundreds and thousands like it, and from all prices...$50 to $50,000 (that last figure is amazingly high, but real nonetheless, for long speaker wire pairs, triamp.).
* Amir, you don't say too much about upgrading AC power cords?