Not everything needs SOTA (State of the Art).

If you control for cost, not only the gap closed, but it switched already.

DeepSeek 4.1 Flash dominates perf/cost for suitable tasks.

And if you do need SOTA, Kimi 3.1 Pro scores 55 on https://artificialanalysis.ai vs 58 of Opus 5.5. And they were released 1 month appart.

Kimi even outperforms Opus on some tasks because it doesn't downgrade its intelligente on cyber and cryptography workloads or ban you if you use it for LLM research.

So the gap is 1 month, or zero, depending on your needs.