Slower Means Faster: Why I Switched from Qwen3 Coder Next to Qwen3.5 122B

I spent about a week running Qwen3 Coder Next on my local rig. Numbers looked great on paper ~1000 t/s prompt processing, ~37 t/s generation. I was using a Ralph-style agentic approach, keeping my manual involvement minimal while the model worked through tasks autonomously. The problem? My backend was crashing constantly. Even when it ran stable for a couple hours straight, actual progress was painfully slow. My experimental project was split into 110 tasks. On a good day, Qwen3 Coder Next knocked out maybe 15 of them. I tried different backends, different configs - same story.