1/ Claude and Codex, but mostly Codex with the Business Plan 2/ No other models 3/ Default CLI most of the time, plus some agent-made tooling for some orchestration 4/ No - frontier models are already super good at this 5/ I'm using Dot, and I find it helpful as a workload dispatcher

I also don't see many differences anymore in the various frontier model - between GPT 6-Sol or Astra or Fable or Opus 5.5... Maybe my tasks are easy enough, or maybe I'm missing a lot here.