Opus 5.5 is a great planner and an expensive typist! Run a whole feature in one session and that's what you pay for: $20 per million output tokens for code Sonnet 5.5 writes at $10. The bill isn't the worst part. One context doing five jobs carries all five on every turn. by hour two it has lost the interface it agreed to and rewritten a function the tests needed. So split the jobs. Opus leads at $4 / $20 and plans, briefs, merges, decides. Sonnet workers do the typing. A verifier checks every claim of done. The catch: a team only pays off on some tasks. the first prompt in the setup exists to tell you when not to build one.