Got down to the metal on a wet ride and as a result I have marked my brake rotor.

Will it make any difference in performance?

yes.its abrake disc

Catastrophically or just a little bit?

A little bit I can live with.

I would imagine it’ll just eat pads a bit quicker.

Ta.

If you can feel the marks with your fingers, like they have rough burred edges, then just wrap some very fine wet’n’dry around a steel rule and gently sand smooth. If the marks don’t have burrs then ignore them, ‘cos sintered pads will smooth them over time anyway. Don’t worry too much about it.

Ta again.

What CountZero said.