My biggest challenge using the api so far was that the output is not reliable. Randomly from time to time it outputs notes and comments even tough I asked to only reply in a code block. Also if I rerun exactly the same promt, it can output something completely different (different content is fine, but I teach chatgpt to follow a structure - it works in 90% of the cases just fine). I’m using 3.5 not 4.
The api can be down regularly. This is annoying especially if you have longer conversations. I had a hard time to resume a conversation. I usually restart the whole process.
However, the overall capabilities are mind blowing. The system surprises me very often.