Do you maybe know how good it is with Apple Pencil? Does it degrade the usability in a noticeable manner?

Yes, it worked for me without any problems.

Works with the Class without problems, I don't notice any difference.

The PanzerGlass fits the iPad Pro Model 2018 and 2020. The iPad Pro 2018 and 2020 have the same dimensions. Even fits with Magic Keyboard! Greetings

Absolutely no problems, important to note, the cut-out for the front camera etc. on the right side ;-) I have both in use.