I know everyone has different experiences, however I've used Mintex on other cars and they were fine, I wouldn't say they were an upgrade but certainly OEM quality.
That said I haven't tried them on the GTI so perhaps the standard OEM compound is better than the Mintex ones.
The devil in me wants to try the grooved discs out
But the sensible head just says keep it standard. I'm only Stage 1 K03 btw.
If I was stage 1 K04 I'd defo be looking for a better pad upfront at the very least.