I’m convinced - when you’re leveraging AI in your workflows, model matters.
I spent hours going around in circles trying to get Copilot with GPT 4.1 to implement something based on my requirements. It kept stumbling on logic issues and making changes, then changing things back, without ever solving the implementation issues.
Eventually, I continued using Copilot, but switched the model to Claude Sonnet 4, and had it solved, completely refactored, thoroughly tested, and documented in under an hour.
Had Claude write a spec so we could implement similar functionality in another language. Got a working, tested implementation in a second language in 20 minutes.
In agentic mode, Claude is eager and aggressive, touching files and making changes even when I ask for suggestions instead of edits. But it’s also effective and fast, and the code it produces is relatively logical and easy to follow.
GPT 4.1 is deferential and follows the rules I set for it, but it’s also slow and bumbling at code-related tasks. The code it produces is overly complicated and difficult to follow.
Both have problems with misplaced brackets and structural syntax issues in larger files. Claude has been faster and more effective at fixing those issues when they happen. Claude is also better at refactoring to break things down and make complex code more maintainable without losing functionality.