GPT-5.5, Opus 4.7 Split Coding Tasks

Benchmarks put these models in the same elite tier, but developer experience says their personalities matter just as much as their raw scores.

• –OpenAI positions GPT-5.5 as its strongest agentic coding model, while Anthropic frames Opus 4.7 as its most capable reasoning and coding model, so this is a top-of-stack comparison, not a niche one
• –GPT-5.5 seems to shine when you need fast unblocking, context-heavy synthesis, and fewer dead ends
• –Opus 4.7 appears stronger when the task rewards persistence and structured effort, but its failure mode is to commit too hard to a bad path
• –For teams building AI coding workflows, this suggests routing by task: one model for exploration and recovery, another for critique and review
• –The practical takeaway is that “smarter” is not the same as “better to work with” in long coding sessions