Opus 4.5 to 4.6 was pretty incremental, I didn't see much of a difference.

The big coding model moments in recent recollection, IMO, were something like:

- Sonnet 3.5 update in October 2024: ability to generate actually-working code using context from a codebase became genuinely feasible.

- Claude 4 release in May 2025: big tool calling improvements meant that agentic editors like Claude Code could operate on a noticeably longer leash without falling apart.

- Gemini 3 Pro, Claude 4.5, GPT 5.2 in Nov/Dec 2025: with some caveats these were a pretty major jump in the difficulty and scale of tasks that coding assistants are able to handle, working on much more complex projects over longer time scales without supervision, and testing their own work effectively.

4.5 is a big jump, but there’s no way 4.5 to 4.6 is what convinced this person.