DeepSeek V4 Pro review: beats GPT-5.5 and costs a fifth of Opus 4.7 We ran 5 developer tasks through DeepSeek V4 Pro, GPT-5.5, Opus 4.7, and Llama 4. V4 Pro beats GPT-5.5 while costing 4.5x less, but latency averages 28 seconds. Apr 29, 2026 · 6 min read model-releasedeepseekbenchmarks