Member-only story
The comeback story is not a leaderboard crown. It is a cheaper path through the same kind of work.
That is why Grok 4.5 is the first xAI model release in a while that I would actually put into a coding-agent routing discussion. Not as a trophy model. Not as a clean replacement for GPT-5.5, Opus 4.8, or Fable 5. As the model that makes the premium coding stack defend its price.
Cursor’s launch chart puts Grok 4.5 at 83.3% on Terminal-Bench 2.1, 64.7% on SWE-Bench Pro, 62.0% on DeepSWE 1.0, and 78.0% on SWE-Bench Multilingual. Artificial Analysis ranks Grok 4.5 (high) #4 of 168 on its Intelligence Index, with a score of 54, 89.5 output tokens per second, and $2 input / $6 output pricing per million tokens. Its Coding Agent Index chart puts Grok Build + Grok 4.5 at 76, tied with Codex + GPT-5.5 xhigh and above Claude Code + Opus 4.8 max at 73.
That is the receipt. The interpretation is more interesting: xAI may finally have a model builders should route against.
Before I get into the numbers, the founder aside: I am Caspar Bannink. I write about AI model releases, agentic coding, and the kind of routing decision a builder has to make when a new model drops. I also build HomeScout, an AI rental search product for Dublin renters. HomeScout is unrelated to Grok 4.5. I post…