Community member u/KienShen published a benchmark evaluating ultra-small language models (4B parameters and below) on AI agent tasks, testing Qwen3.5-4B, Spark-X2.6, LFM3-1.7B, LFM2.5-2.6B, Gemma 4 E2B, and MiniCPM5-2B. The assessment highlights distinct strengths and weaknesses across models, noting a rapid increase in the "intelligent density" of compact architectures. Full results and methodology are available on the author's blog.