(Spectra/Dyneema rope generates a much more obvious thump than steel.)

Even when it breaks at the winch end? I wouldn't know - I've not yet
flown on the stuff.

It doesn't matter where it breaks - the whole rope weighs around 30
Lbs so the feel in the glider is the same.


Assuming the pilot is monitoring airspeed, a power fade means the nose
will coming down and be down to a normal glide attitude and airspeed as
power is totally lost - just as at the top of a normal launch.

If its a slow fade the airspeed may easily be lower than approach speed.
IME a slow fade is harder to recognize and deal with than a sudden cut or
a break.

Not if the pilot is controlling, or just monitoring, the airspeed.
The pilot will lower the nose appropriately to maintain the selected
airspeed. When the power is all gone, the glider will be gliding at
the selected speed - a perfect recovery even if the pilot didn't
recognize the power failure. Lowering the nose is the signal for more
speed so it works in all cases.