Claude is highly autonomous. You can yeet short underspecified prompts at it, and it's tuned to produce good vibe code output, though very samey since they've squashed the distribution a bit in order to effectively steer the model. GPT5 is less autonomous and also needs more steering, but the upside of this is that when Codex can't do something, it'll come back to you for feedback, whereas when Claude cant' do something it implements a toy/mock version then typically lies about completing the task successfully in the final summary output.