I've been running all three frontier models in production across my AI Business Platform, KCAI Desktop, and Memory Forge. Here's what I've actually observed — not benchmark scores, but real task performance.
Coding Performance
For complex multi-file refactoring, the ranking is clear. GPT-5.5 handles context across 50+ files with its 256K window.
The Verdict
There's no single winner. The optimal setup uses all three for different tasks.