What's the difference between 0.5% distortion and 0.5% distortion?
Is it a trick question as the two numbers seem identical? No, I use this as an example to make a point.
If the output of my Power Plant is trending down, from 1% to 0.5% I am happy. If my Power Plant is trending up from 0.1% to 0.5% I am worried. The number we are working with is identical, it's now the trend we are concerned with. The direction of the movement is what we are now focusing on not the actual number itself. So if you start with 5% distortion on your power line and a product lowers that number by ten times, that's a good trend.
When it comes to absolute numbers, how you are feeling about those numbers has a lot to do with your attitude towards the equipment at hand.
Trends matter more than absolutes in the long run.