Confirmed: GSQ-RCO IQ3_S for Qwen3.8 Flash Next is excellent.
It’s slightly larger than UD Q2 K XL, but significantly better in both token efficiency and accuracy.
I was only able to evaluate four models on agentic coding, but clearly models that performed well on non-agentic evals, such as the Q1 variants, can perform poorly on long-horizon tasks.
Based on these results, I wouldn’t go below IQ3_S, in terms of size, if you expect performance reasonably close to the original model.
I’ve updated my article on these GGUF models with more details:
(in the chart below the model sizes exclude the ngram table)