My errors are mostly missing s in verbs, like "The dog eat[s] a lot of meat." , also wrong prepositions like "I'm still thinking [in->about] the exam." and sometimes idioms. I like it [the free version?] as an advanced orthography/grammar corrector for details, not a whole rewrite.

I agree with you. I remember a recent discussion where someone "cleaned" the comment of other user using AI, https://news.ycombinator.com/item?id=47201796 the cleaned version was soulless or as the comment says wooden.

EDIT: From a recent comment by myself:

> People here is friendlier when the author is in the comment section replaying questions.

This time I notice the error on my own, but I made similar silly mistakes in the past. Google Docs may show a line with a suggestion to fix it.