I had similar experiences with ChatGPT 3.5 in the past. I was feeding it matrices and it was consistently generating wrong answers with calculations. I swear I would never use it again. Then came ChatGPT 4.o. I think for people who want to learn a foreign language it became useful and funny. Plus it became useful for math, at least for me. I do calculations and I check my results with those of ChatGPT. If it matches, I consider it is likely correct, else I re-check. After re-checking if it still doesn't match, I keep my calculations and ignore those of ChatGPT. This way I never got disappointed anymore with it, since I use it as a tool to do double checks.

For coding, I feel like Claude can also give valuable answers sometimes better than ChatGPT. Recently I asked both to build an algorithm to convert a Golang algorithm to Python to encrypt passwords... And the results were consistently 100% totally wrong. Very disappointing isn't it? But in this case I was double checking with a good Golang version by decrypting the encrypted password. So with this kind of check I could immediately spot incorrect code. Disappointing but fine since the only negative impact was to lose a little bit of my time working on it. Bottom line regarding code, Claude can be good as well but currently more expensive, and regardless this is really important to have unit tests or some kind of test to double check results.

So for coding I use it more like a very advanced auto-completion tool. E.g.: I want to read a CSV file and parse it a particular way, then it gives me the code right away. Or I want to write a SQL statement to show some statistics about a metric, it writes it. Its use is tremendously good to save time but everything has to be constantly double-checked by testing the code, or by doing a quick visual check, or by comparing carefully results if money is involved and it is extremely important that the code must be right.