Not super common or super niche. I use R. And it completely made up code a year ago. Sometimes I still does, but less. And when I ask it for citations it can make shit up too. I really stand by the assertion that it needs a lot of babysitting.

But, between it getting better and me getting better at asking and some patience, I get what I want. But, it does require a lot of fine tuning and patience. But its still just faster than googling.

If you feed it in documentation or ask it to search for its answers in substack (or really just whatever search constraints you want) and then tell it to give you the links it used, you might have a better time. This forces it to look up an answer instead of hallucinate one.