Speaking of performance wall: The Claude 4 results were added to the Aider LLM Leaderboard [0] yesterday. Opus 4 is clearly below Gemini 2.5 Pro at almost twice the price. Sonnet 4 fares worse than Sonnet 3.7, with the thinking version of Sonnet 4 being somewhat cheaper than its 3.7 counterpart.
[0] https://aider.chat/docs/leaderboards/