RTX 3090 local coding-agent bake-off: Qwen3.8-27B Q4 + llama.cpp ~59 tok/s with reliable tools

@Brjen’s team spent a week comparing local coding-agent stacks on one RTX 3090 (24GB). Winner: Qwen3.8-27B Unsloth UD-Q4_K_XL with llama.cpp (65k context, q8 KV, native MTP depth 2, fully on GPU). Real multi-step coding runs hit ~59 tok/s (~46 tok/s at 45k context) and passed nested tool JSON, fixing a failing test, and a clean unified diff. They rejected Q3 for bad tools, heavier quants for context/MTP tradeoffs, and Flash-Next setups that needed CPU offload.