Comment by Mazer23

We tested this on our agentic CAD modeling harness. Opus 5.5 seems to be a pretty dramatic improvement in spacial reasoning and CAD coding. Our go-to is still Gemini Flash 3.8 for speed and cost reasons, but Opus 5.5 is a big update.

https://www.partforge.ai/blog/2026-09-23-new-model-day