Sonnet is better than 4o for virtually all use cases.

The only reason I still use OpenAI's API and chatbot service is o1-preview. o1 is like magic. Everything Sonnet and 4o do poorly, o1 solves like a piece of cake. Architecting, bug fixing, planning, refactoring, o1 has never let me know on any 'hard' task.

A nice combo is have o1 guiding Sonnet. I ask o1 to come up with a solution and explanation, then simply feed its response into Sonnet to execute. That running on Aider really feels like futuristic stuff.