Quote Originally Posted by nick250
You have learned that line conditioners can not due signal processing and alter what you see on your TV or what you hear from your speakers.
That might be a slight over generalization

Line conditioner/filters can be useful if stability/noise of AC line is in question-such as light dimming/brightening when an appliances is turn on/off, and/or live close to large factories where AC line might be too polluted.

But for most instances (as you pointed out), it might not be necessary. Just make sure to get a good surge protector