For one off scripts or sketching a concept quickly it’s good enough, and for language reference it’s generally useful.
However, one thing I’ve noticed with Claude in particular is it tends to overweight the top answers in stack overflow.
The problem there is top answers are rarely the best answer - rather they tend to be overly verbose and long, whereas the best answer is usually the second one that just tells you what function to call.
On multiple occasions I’ve had Claude answer a simple prompt with horribly verbose and complicated code.
Then I’ll say “what about this single call?” (Eg the type of SO answer than gets the second most votes), and it’s says “You’re right! That’s a much better answer”.
Likewise I suggest to anybody to take the domain you are most knowledgeable in and pepper your LLM of choice with lots of questions and see how much it knows.
You’ll get a feel for how much you can trust it in other domains - which is “not much”.