@simon
In my brief exploration of it (and based on others experience) it seems to be a direct replacement of Stack Overflow.
That is, if you use reasonably mainstream technology, and you want help in solving a common problem or implementing a standard solution, perhaps with a small twist, then it's helpful and generally correct.
But as you veer off the mainstream path, the suggestions rapidly become misleading and wrong, and it's faster figuring it out for yourself.
@jannem I’ve not been finding that myself - sure, it’s best at Python and JavaScript and SQL but I’ve been getting great results for languages I don’t know well (or at all) like Go and AppleScript
You gotta get good at testing what it proxies, but that’s a similar skill to code reviewing code by other people