GPT-5.5 Tops Benchmarks, Costs 2x API Price, Still Hallucinates

OpenAI launched GPT-5.5, an agentic model that tops Terminal-Bench 2.0 at 82.7% and surpasses Claude Opus 4.7 and Gemini 3.1 Pro on coding and math. However, independent testing shows higher hallucination rates and effective API costs 20% above GPT-5...