Claude Code and GitHub Copilot using Claude are not the same thing
Stop telling me “GitHub Copilot can use Claude, so why would I buy Claude Code”. There’s about a million reasons why you should stop using GitHub Copilot, and the main one is that it’s not a good product. Sorry not sorry Microsoft.
Over and over again I’ve heard how much coding agents suck (often from .NET devs), and the bottom line is they’re doing it wrong. If you aren’t at least TRYING multiple coding tools, you’re doing yourself a disservice.
This may sound a bit contemptuous, but I mean it with love - .NET devs LOVE to be force fed stuff from Microsoft, including GitHub Copilot. Bonus points if there is integration with Visual Studio. (The “first party” problem with .NET is a story for another time.)
I ran a poll on X asking .NET devs what AI-assisted coding tool they mainly use. The results speak for themselves - nearly 60% use GitHub Copilot, with the balance being a smattering across different coding tools.
(I know I’m picking on .NET devs specifically, but this applies equally to anyone using a generic one-size-fits-all coding tool. The points I’m making here are universal.)
Here’s the bottom line: GitHub Copilot will not be as good as a model-specific coding tool like OpenAI’s Codex, Claude Code (which is my preferred tool), or Google’s Gemini.
Why?
- Sonnet 4.5 is trained to specifically use the toolset that Claude Code provides
- GPT-5-Codex is trained to specifically use the toolset that Codex CLI provides
- Gemini is trained to specifically use the toolset that Gemini CLI provides
OpenAI has explicitly said this is the case, even if the others haven’t.
“GPT‑5-Codex is a version of GPT‑5 further optimized for agentic software engineering in Codex. It’s trained on complex, real-world engineering tasks such as building full projects from scratch, adding features and tests, debugging, performing large-scale refactors, and conducting code reviews.” (Source)
Why not Copilot?
- Giving several models the same generic toolset (with maybe some different prompts with a different model) will simply NOT work as well with an LLM as specific training for a specific toolset.
- Model selection paralysis - which model is best suited to which task is really left up to the user, and .NET devs are already struggling with AI as is. (This is totally ancedotal of course, but I talk to LOTS of .NET devs.)
- Microsoft has married themselves to OpenAI a little too much, which means their own model development is behind. I know it feels good to back the winning horse, but I’d love to see custom models come out of Microsoft/GitHub, and I see no signs of that happening anytime soon.
My advice
- PAY THE F***ING $20 A MONTH AND TRY Claude Code, or Codex, or Gemini, or WHATEVER. I happily pay the $200/month for Claude Code.
- Get comfortable with the command line, and stop asking for UI integration for all the things. Visual Studio isn’t the end all be all.
- Stop using GitHub Copilot. When it improves, I’ll happily give it another go.