Now, change the input signal to a 1600Hz toneburst. Whereas the output of the low-pass filter will begin to change just as soon as the leading edge of the toneburst arrives (ignoring propagation delay, i.e., the speed of light), absolutely nothing will come out of the second filter until 156.25uS have passed. So, while both filters have a delay, in some qualifiable way, the nature of the delays is different. I suppose you could say, sT compared to 1 / (1 + sT).

Anyway, I guess I'm getting a bit too esoteric. It's just something I started thinking about after reading your article. Again, sorry if this is inappropriate material for the forum.