A comparison of GPT-6 Astra and GPT-5.6 Sol code review models found that despite Astra's 2.5x higher cost and superior precision (95% vs 85%), Sol identified more confirmed bugs across 50 pull requests (107 vs 91) at lower cost per bug ($0.039 vs $0.062). The study highlights that meaningful code review evaluation requires measuring both bug detection and false-positive rates, not just raw findings.