Nice writeup.

This may nudge me to start using chatbots more for this type of queries. I usually use Perplexity or Kagi Assistant instead.

Simon, what's your opinion on doing the same with other frontier systems (like Claude?), or is there something specific to ChatGPT+GPT5?

I also like the name, nicely encodes some peculiarities of tech. Perhaps we should call AI agents "Goblins" instead.

I've been much more impressed by GPT-5 than the other systems I've tried so far - though I did get a surprisingly good experience from the new Google AI mode (notably different from AI overviews): https://simonwillison.net/2025/Sep/7/ai-mode/