Your post is causing me to muse. Is digital harder to transmit than analog?
Digital is a series of steps, like a square wave. Square waves start and end with an "infinite" frequency," the rise and fall of the square wave. This is hard to achieve without some delay, that is, a finite rise time.
Trying to remember some of what I learned in school, transmission lines need to be terminated properly. Any mis-match in impedance between source and cable or cable and termination (destination) causes reflections (echoes) back the opposite direction, smearing of the signal.
So IF I have had enough coffee, the source impedance and destination impedance are as critical as the velocity of propagation, intrinsic impedance (same as the source and destination impedance) and the cable capacitance.
This leads me to believe a good digital cable should be a well engineered device for proper operation. Maybe they should include their own termination device?
There was some fooling around with a slotted line and a TDR in the lab that week. It had a lot to do with standing waves. And it is time for more coffee.