Ask HN: What default model do you use and why?

Developers on Hacker News discuss their preferred default AI models, with Claude and its Opus variants emerging as popular choices due to cost-effectiveness and reliability, while others prefer faster alternatives like Gemini's Flash models or DeepSeek. Common concerns include balancing model capability with cost, avoiding overly complex models for straightforward tasks, and challenges with autonomous model performance creating technical debt that requires manual oversight and testing frameworks.