ChatGPT GPT-5 Review 2026 — What's New, Benchmarks & Is It Worth Upgrading? GPT-5 is OpenAI's most capable model to date — smarter, faster, and more reliable than GPT-4o. This full review covers what's new in GPT-5, benchmark performance, real-world testing across writing/coding/reasoning, pricing, and whether it's worth upgrading from GPT-4o. GPT-5 vs Claude 3.7 vs Gemini Ultra Benchmarks Anthropic vs OpenAI vs Google ChatGPT Custom GPTs Guide AI Hallucinations Explained GPT

The definitive 2026 benchmark comparison of GPT-5, Claude 3.7 Sonnet/Opus, and Gemini Ultra across reasoning, coding, writing, multimodal tasks, long context, and real-world use cases.