alt Hacker NewsThat's a really interesting experience. Lots of people in language learning communities have this argument back and forth for years. Have you ever written a longer piece about your education, preparation for the exam, abilities of other test takers?
For reference I scored ~C1 in German years ago (testdaf 4/4/5/4) and at that level there's no question at all about the vast gulf between me and an educated native speaker.
I've not written up anything, no. I think I'd have a hard time doing so without just feeling like I'm bragging about myself, which I don't like.
There's still a definite gap between me and native speakers, that shows itself primarily in the effort required, but I'm definitely near native (pass as German in all social settings, although an hour long conversation will usually tease it out due to my unfamiliar first name or small-talk topics, rarely but occasionally due to mistakes).
I prepared by doing two practice exams and about 5 filmed and timed practice presentations, and that was over preparing for me. Experiences vary, and I do think I'm a bit towards the outlier side, but it's left me convinced that the whole "native speakers might not pass C2" thing is overblown.