I'm still using DS-flash - it beats frontier model on speed and cost keeping good enough code quality. It depends on the harness and constraints you give to the model but for most of the tasks its a great fit, I have not switched from DS since couple of weeks already (previously I would switch to Opus for some heavier work but I stopped recently).

My harness consists of multi-level AGENTS.md and SOUL.md containing "grug brain developer" and "asd-ste100" type of speech for clearer communication.