I've tried all of the above. I've asked it to summarize information about what languages in a class had strong symmetric multiprocessing characteristics and it made up over half of the details. I've asked it to generate code for a simple linked list and it created garbage. I've asked it to summarize what code does and it gets it blatantly wrong.

These are just a few examples. I've found it to be nearly useless for anything where a semblance of correctness matters. Every single thing it says must be validated against external sources and it can easily lead you down rabbit holes.

GPT-4 was a little better than 3(.5), but I've yet to see it be good at anything enough to warrant the price tag or the time.