ran Opus 5.5 and GPT-6 Sol side by side, here's what actually separates them Opus 5.5: - Anthropic's frontier model, beats Fable 5.1 across nearly every benchmark, agentic coding 66.4% vs 55.8% - 40% cheaper than Opus 5, $4/$20 per million tokens - noticeably less verbose, leads with the actual answer instead of burying it - takes longer on complex tasks, 35 min and ~200K output tokens on a Blender scene, but the extra thinking shows in the output, full walkable game environments, near-exact SVG logo recreation GPT-6 Sol: - sits below GPT-6 Astra, a cheaper, faster tier, not OpenAI's top model - $2/$10 per million tokens, a fraction of Astra's $10/$50 - deception rate dropped from 10% to 1.3% gen over gen - hits a real chunk of Astra's performance at a much lower cost, ~30% on automation bench for about 25 cents where Astra-level performance runs closer to a dollar the real fork isn't which model is smarter, it's what tier you're actually comparing Opus 5.5 vs Sol 6: different weight classes, one's a flagship, one's a budget tier Opus 5.5 vs Astra is the fairer fight, Opus 5.5 leads on coding depth and design quality, Astra stays cheaper and faster per task for high-volume, low-complexity work: Sol or Luna. for tasks complex enough that longer thinking time pays off in output quality: Opus 5.5