I agree, codex is great at reviewing as well. I think that’s because code is the ideal description of what we want to achieve, and codex is good (only) when it knows what must be achieved, as verbosely as possible.
Currently I don’t let GLM or Opus near my codebases unsupervised because I’m convinced that the better the foundation, the better the end result will be. Is the first draft not pretty crappy with GLM?