Because of this change, you have to consider three things when deciding what AI to use: Models, Apps, and Harnesses. Models are the underlying AI brains, and the big three are GPT-5.2/5.3, Claude Opus 4.6, and Gemini 3 Pro. These are what determine how smart the system is, how well it reasons, how good it is at writing or coding or analyzing a spreadsheet, and how well it can see images or create them.
