A UC Berkeley study finds the harness sets the price of an answer : GPT-5.6 Sol costs 71% less on Pi than on Claude Code, the same model returning the same result, & none of the 42 harness comparisons shows a statistically significant quality difference. Two startups bidding on the same $250k contract earn 38% & 75% gross margins depending on what they built around the model, & the cheaper one pays back its sales cost in half the time. Effective harnesses take a deep customer understanding, relevant evals & a factory for automating hill climbing.