We tested six of 2025's most talked-about AI models in a proper head-to-head comparison — GPT-5, Grok 4, Claude 4, Gemini 2.5 Pro, Manus AI, and DeepSeek — using real business tasks, no marketing fluff. GPT-5 won overall for versatility, but Grok 4 dominated creativity, Claude 4 owned fact-checking, and Gemini 2.5 Pro nailed coding. For UK businesses choosing AI tools, this cuts through the hype to show which models excel at what.