My vouch works well, but I barely use it: mostly on select comments of shadowbanned users. My flag, on the other hand, feels like it requires heavy consensus: even when it's successful, the comments I flag tend to get vouched back into existence on a hair-trigger.

I have, but it's definitely very rare. And might have been manual intervention as described above.

Personally, I've seen two - both ones that I emailed about (and I really disliked the stance taken on one of those, but they were debating at a level that was polite, addressed objections raised, acknowledged other PoVs etc.)

Vouch, I've perhaps seen reverse things several times (more of a background observation not pursued, so, you know, fuzzy anecdata at best), I did get feedback from @dang that one comment I vouched for was, in fact, a legitimate AI gen comment .. so clearly I'm human enough to fall for the occasional clanker.