GPT-4 was already a massive improvement on 3.5 in terms of replying consistently in a certain JSON structure - I often don't even need to give examples, just a sentence describing the format.

It's great to see they're making it even better, but where I'm currently hitting the limit still in GPT-4 for "shelling out" is about it being truly "creative" or "introspective" about "do I need to ask for clarifications" or "can I find a truly novel away around this task" type of things vs "here's a possible but half-baked sequence I'm going to follow".