Choosing the right AI writing assistant depends on your specific use case. Claude 3.5 Sonnet excels at nuanced technical explanations, long-form content with consistent voice, precise language, and code documentation. GPT-4o is stronger for creative marketing copy, ad headlines, and diverse format experiments. Gemini Ultra with Google Search integration provides the most current and factual information for research-heavy content. Context lengths: Claude 200K, GPT-4o 128K, Gemini 1M tokens. Recommended workflows: technical documentation with Claude, marketing content using GPT-4o for concepts then Claude for refinement, research reports with Gemini for data then Claude for synthesis. For high-volume production, build an orchestrator that routes tasks to the optimal model based on task type.