I used Cline+Claude 3.7 Sonnet for the initial draft of this LLVM PR. There's a lot of handholding and the final version was much different than the original.

https://github.com/llvm/llvm-project/pull/130458

Right now I'm using Roo Code and Claude 4.0. Roo Code looks cooler and draws diagrams but I don't know if it's better.